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Odp: [NASA Gravity Assist] : Season 5
« Odpowiedź #45 dnia: Sierpień 06, 2023, 07:49 »
jak poszukiwać technosygnatur na egzoplanetach ?
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Ravi Kopparapu: So if you find CFCs [chlorofluorocarbons] and you think, oh, maybe that's a technology, then you want to find corresponding other kind of pollutants in your data. And maybe for that you need to have a different kind of a telescope to do that, because not everything will be seen at the same time. And so if you find several different signatures of gases, if you do find other pollutants, then you know, hey, you know, there's something going on that planet. Yeah, that's great.

Gravity Assist: Do Other Planets Make Pollution? With Ravi Kopparapu (1)
Apr 8, 2022


What do planets outside our solar system, or exoplanets, look like? A variety of possibilities are shown in this illustration. Scientists discovered the first exoplanets in the 1990s. As of 2022, the tally stands at just over 5,000 confirmed exoplanets. Credits: NASA/JPL-Caltech

On a quest to find out if we are not alone in the universe, Ravi Kopparapu at NASA Goddard studies how we could use telescopes to detect signs of life beyond our solar system. These include both signs of biology and technology, since there are certain kinds of signals and chemicals that do not occur naturally. Learn about the planets that are most exciting to Ravi and how science fiction inspired his journey to become a scientist.

Jim Green: Is there intelligent life beyond our solar system? And how are we ever going to find it? 

Ravi: No one signal is a good signature of technology or biology. You need a combination of things.

Jim Green: Hi, I'm Jim Green, and this Gravity Assist, NASA’s interplanetary talk show. We’re going to explore the inside workings of NASA and meet fascinating people who make space missions happen.

Jim Green: I'm here with Ravi Kopparapu. And he is a scientist at NASA's Goddard Space Flight Center, who thinks a lot about the signs of life and what they might be on a planet outside our solar system. We call that planet an exoplanet. Ravi makes climate models of exotic faraway worlds and investigates how we could detect biology, but also technology, coming from these exoplanets. Welcome, Ravi, to Gravity Assist.

Ravi Kopparapu: Thank you, Jim. I'm super excited to be here.

Jim Green: Well, you know, I heard that you used to study something completely different: gravitational waves. What are those? And, and why did you stop working on that particular topic?

Ravi Kopparapu: Yes. (laughs) So I did my PhD in physics, in the field of gravitational waves. To give a brief summary: Imagine you're throwing a rock into a clear water. And the ripples after you throw the rock into the water, the ripples coming from there are essentially what we think of as gravitational waves coming from an object. Any object in this universe has gravity. And so gravitational waves are essentially when you have a moving object, they're very dense moving objects, going around each other, or, you know, exploding stars. They emit these spacetime waves, you know, Einstein theorized that there could be spacetime, right? So these are the spacetime waves traveling across the universe.

Ravi Kopparapu: Why did I leave this field? I was at Penn State working as a postdoc on gravitational waves. But at that time, I heard about this new field of science that's just coming out exoplanets. And I was like, Okay, wait, this sounds interesting. And the main thing I wanted to do is that, can I explain my work to my mother? And if she asked me, “Hey, Ravi, what are you doing?” And I'll say, “Oh, I'm working to find alien life.” And that’s simple for me to explain to her. And it was exciting. And my daughter used to say that, you know, “my dad finds aliens.” I felt like a Hollywood star. And so I thought, “Okay, let's go ahead and do it.” And then that's how I started.

Jim Green: Well, that's fantastic. But you're really doing it in a very important way. And that is looking at atmospheres of exoplanets, and not just any old atmosphere. How did you end up making that decision?

Ravi Kopparapu: Right. So the reason why I study these atmospheres of exoplanets is because I think, the ultimate goal of answering the question, “Are we alone in this universe?” with the existing telescopes and existing instruments, is to look at the atmospheres of these exoplanets because they're so far away, it's really not likely anytime soon for us to travel to those planets, right? And so the best thing we can do at this point is to point our telescopes collect the light coming from the atmospheres of the planet, and then look [at] what kind of gases they are. And that was exciting to me. And so I started working on the climate models of these planets.

Jim Green: Well, why do you think, and I believe it's the majority of planetary scientists and astrophysicists think that there could be complex or intelligent life on planets beyond our solar system?

Ravi Kopparapu: So, just to give you an idea, right now, we know more than 5000 exoplanets, planets orbiting other stars. On average now  we think there is at least one planet for every star in our galaxy. And our galaxy has at least a minimum of 100 billion stars. So there are at least 100 billion planets in our galaxy. And imagine the statistics of having so many planets around in our galaxy, and many of them could be smaller, Earth sized planets that could host life.

Jim Green: Well, I know you've done some really fascinating work on exoplanet climate models. What are some of the climate conditions you expect on these exoplanets?

Ravi Kopparapu: If you asked me this question, 30 years ago, I would say oh, all of them are going to be Earth-like, conditions or maybe you know, Jupiter-like planets, because how else plants are going to form other than our solar system arrangement, right? I mean, come on. Everyone should look like us. Right?

Jim Green: Right. Right.

Ravi Kopparapu: Of course.

Jim Green: (laughs)

Ravi Kopparapu: But then what guess what happened in 1995? When they first found the exoplanet the first exoplanet around a sun-like star, it's a Jupiter sized planet, in a four-day orbit around a sun like star.

Jim Green: Wow.

Ravi Kopparapu: Yes. And it was unexpected. And that's why we wanted to see how these planet conditions are going to change from star to star. What we are seeing is only a small subset of the climate conditions that we are discovering right now. Super-hot, small-size, planets, large size planets, and also habitable Earth sized planets are also we found them and with lots of different kinds of missions. One important thing though, Kepler Mission, which was launched in 2009, found that the most common type of planet is some were in between Earth and the Neptune size. And we don't have that in our solar system.

Jim Green: So yeah, we call that a super-Earth or a mini-Neptune.

Ravi Kopparapu:  Exactly.

Jim Green: Yeah. So something happened as our planets evolved, that that one of those didn't form. Well, what do you think that was?

Ravi Kopparapu: Those kinds of planets are somewhere in between, transitioning between a gas giant and a rocky planet. They don't have as dense atmospheres as Jupiter or Neptune, or they don't have completely thin atmospheres like our Earth. They have somewhere intermediate between both the planets. They may have little of hydrogen, little of, you know, carbon dioxide or ammonia, but not too much, not too little.

Jim Green: Yes, that's what makes them fascinating, that we don't see them in our own solar system, but we can see them around other stars. Well, are there any exoplanets that you're really excited about right now?

Ravi Kopparapu: Yes, actually. Our closest star is Proxima Centauri. And four or five years ago, astronomers have discovered a planet, an Earth-sized planet in the habitable zone around Proxima Centauri. It's called Proxima Centauri b. So this is what I'm really excited about, that opportunity right now.

Jim Green: Well, that star and the planet is only about 4 light-years away. There's another planetary system a little further that I'm also excited about and that's TRAPPIST-1, and that's it about 40 light-years away. What can you tell us about the TRAPPIST-1 system of planets?

Ravi Kopparapu: So you asked if I'm excited, and what kind of a planet I’m excited about. I said Proxima Centauri b. Well, we won't be able to characterize or at least look at the atmosphere of the planet in the next decade or so. But for TRAPPIST, we have James Webb Space Telescope up there, and it is one of the primary targets in the habitable zone planets with James Webb Space Telescope. So there are seven planets in that system.

Ravi Kopparapu: TRAPPIST-1 system has three habitable zone planets in it.

Ravi Kopparapu: We would like to see if the planets themselves can retain the atmosphere, because the star is pretty small. And these small stars usually have very high flaring and ejections of very high intensity X-rays and the UV rays. So we would like to see, first of all, do they have any atmosphere? And if they do, do they have water-based atmosphere? Because water is essential for life.

Jim Green: It turns out that star, as you said, is a small dwarf star, those planets are really close. And like our Moon, are they tidally locked? Do they always have one face pointing to the star, and the other pointing away?

Ravi Kopparapu: Yes, they are tidally locked. In fact, I would even go ahead and say they are synchronously rotating. Essentially what it means is what Moon is doing to us, always facing the same side of the planet to the star. And because of that, so this is exactly what I do in my research work in my climate modeling. We model these tidally locked planets around these cool stars. And, and because these planets are tidally locked, or synchronously rotating facing only one side all the time, the the climate and the weather is completely different than what how we have it on Earth. For example, if you're on that planet, there is always a thick cloud cover right in front of the Sun side of the planet, always all the time. And because of that, that cloud will try to protect or at least try to not increase the surface temperatures as much as it would have if you if you don't have the cloud cover. And so the climate is totally different.

Jim Green: What is the concept of this habitable zone around a star?

Ravi Kopparapu: So the way we define in the exoplanet field, the habitable zone is, it's the region around a star, where a rocky-size planet with suitable atmosphere also has liquid water on its surface, and you can see how I carefully try to craft this definition. Well, liquid water is essential for life. And so we want to see if there is liquid water on the planet. Why surface? Why not subsurface? Well, these planets are exoplanets. They are quite far away from us. So within our solar system, there are Jupiter's moons and Saturn moons where we think there are, there is subsurface, liquid water. So we have the luxury of sending missions to those planets and see if we can find the water under these moons. We don't have that kind of luxury for exoplanets. So we have to focus only on the surface liquid water. And that's the reason why we focus habitable zone concept on that.

Ravi Kopparapu: We have to understand that our Earth's example is only one possible way of having life and intelligent life. So every planet’s evolution would be different. So that that that's something that when we have to look when we are looking for exoplanet life.

Jim Green: Yeah, in fact, one can also think that we actually co-evolved with the Earth. We were in the right place, the right time, our moon helped us in many different ways. Our climate was great. And that really enabled us to develop into intelligent beings. This brings up a really fascinating topic in that is, how might we detect signs of technologies developed by intelligent beings on other planets around other stars? And we call that technology technosignatures. So what kind of technosignatures should we be looking for?

Ravi Kopparapu: So we know already one technosignatures that several of our colleagues are doing the radio technosignatures, radio, it's called a SETI search for extraterrestrial intelligence. There are other ways that we can do, for example, pollution on the planet produced by industrialized civilizations. Maybe they have some sort of laser pulses sending as a beacon towards us. We can also detect them with the night-side city lights. Every civilization needs energy to produce and you know, to sustain. If we can build a telescope and look at the planet and if we detect nightside city lights, we know a that's one of the technosignatures. So there are several of them like that.

Ravi Kopparapu: Chlorofluorocarbons, the CFCs that we use in our refrigerants, there is nothing in the nature that we know of, and that we can think of that can produce CFCs naturally, biologically, or hey, even abiotically. There is only one way to do that. And that's through technology -- that we know of.

Jim Green: That begs the question then, what would be the next set of observations you would then make?

Ravi Kopparapu: Okay, this is even, another excellent point. No one signal is a good signature of technology or biology, you need a combination of things, okay.

Ravi Kopparapu: So if you find CFCs [chlorofluorocarbons] and you think, oh, maybe that's a technology, then you want to find corresponding other kind of pollutants in your data. And maybe for that you need to have a different kind of a telescope to do that, because not everything will be seen at the same time. And so if you find several different signatures of gases, if you do find other pollutants, then you know, hey, you know, there's something going on that planet. Yeah, that's great.

Ravi Kopparapu: One of the important things that we have to do is to remove or identify false positives.

Jim Green: Now, what do you mean by that? (laughs)

Ravi Kopparapu: Ah, that's a good point. And, and also false negatives. I'm going to say about both them,

Jim Green: Okay, okay.

Ravi Kopparapu: Okay. The false positive is that you detect a signal, and you think it is your, the signal that you want, you know, “I found an alien technosignature or something.” But then it turns out to be out something the nature produced, or maybe some instrumental problem. So that's a false positive. False negative is, you detect something, and you say that, “Oh, it's  instrumental noise. It's nothing there. It's from coming from the star.” But it actually is a signal from the thing that you want to detect!
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Odp: [NASA Gravity Assist] : Season 5
« Odpowiedź #46 dnia: Sierpień 06, 2023, 07:49 »
Gravity Assist: Do Other Planets Make Pollution? With Ravi Kopparapu (2)


Dr. Ravi Kopparapu studies climate models of exoplanets at NASA Goddard Space Flight Center. Credits: NASA

Jim Green: Yeah, I'm concerned about that, too, as you probably know. You know, we have to be able to be confident, you know, create a level of confidence in each one of the observations. But what's exciting about the field is, we make these analyses on signals, we get that out, the scientific community thinks of new and inventive and creative ways to either disprove the idea or enhance the idea. And that's the process of science that we want to have.

Jim Green: Well, I have to tell you, you know, they'll come a time when we may have to say we're very confident that we have seen signs of extraterrestrial life. Do you think we humans, as a civilization here on Earth, are ready for that news?

Ravi Kopparapu: I think we are ready.

Jim: (laughs)

Ravi: I one-hundred-percent believe we are ready. And I'll tell you why.

Jim Green: (laughs) Okay, because I've been asked that. And I've said I don't think we're ready. So, so I'm very fascinated to hear your response.

Ravi Kopparapu: Okay, so I like to say this: With the discoveries of exoplanets and with the discoveries of, you know, habitable zone, Earth, with water on Mars, and every aspect of science, we are not suddenly breaking out. It's not 30 years ago, if you say that, Oh, we found a life on other planets, then everybody -- “Oh, what? What did you do?” So here we found we are saying that okay, we found several thousands of planets. We are inching closer and closer. So we are getting everyone ready to accept to the point that “hey, you know, just, we are finding lots of neighborhoods, we are finding lots of houses. It's just a matter of time before we find people in those houses.”

Jim Green: Okay.

Ravi Kopparapu: So I think we are ready.

Jim Green: All right. I don't think we're ready. And the reason why is I'm not sure what the observations are that will be the smoking gun that tell us what we've really found when we actually make the announcement and that's going to require a lot more educating everyone as to what we've really measured and why we really think we have a high level of confidence to determine that it's life.

Ravi Kopparapu: Okay, that's a scientists’ problem.

Jim Green: (laughs)

Ravi Kopparapu: Not the general public’s problem. (laughs)

Jim Green: (laughs) Okay, okay.

Ravi Kopparapu: (laughs)

Jim Green: Well, you know, I've also heard that you've been involved in looking at unidentified aerial phenomena or UAPs. And and you're approaching that from a scientific perspective, of course. Can you tell us a little bit about that?

Ravi Kopparapu: So this is what I say, when we talk about the UAPs and search for life. They are two completely independent topics. We cannot combine them, unless we have super compelling information that, okay, they are somehow connected. For me, the search for life is what we just talked about all this time, exoplanets and telescopes and instruments and whatever. UAPs are something that are in our skies, and we don't know what they are.

Ravi Kopparapu: And essentially, that's where I stop and say, okay, because we don't know what they are, we have to observe them with different instruments, collect the data, analyze, and then you figure out what they are. Apart from that everything else is speculation. And this is what I call a scientific applying a scientific methodology to studying the UAPs.

Jim Green: These UAPs may not be technological in nature. The many possibilities are atmospheric events or other natural phenomena. We just don’t know yet. 

Jim Green: Well do you have enough data to make a determination? Or do we still lack a lot of knowledge and observations of UAPs, to make a determination?

Ravi Kopparapu: I think we do need a lot of data, collection of data, before we do any kind of determination. And that's where we are right now collecting the data.

Jim Green: Well, Ravi, I always like to ask my guests to tell me what that person place or event was that got them so excited about being in the sciences that they are today. And I call that event a gravity assist. So Ravi, what was your gravity assist?

Ravi Kopparapu: My gravity assist, there were two of them. One, before I entered my PhD program. I'm a big fan of Star Trek. And I felt that that was a community where I could relate to and I wanted to study life from, you know, other planets. And that really, really motivated me since I was in eighth or ninth grade. And, and that really motivated me to pursue science, math, physics, and I was told to do well in those to become a scientist. And I kept that goal all the time, all, all through my life.

Ravi Kopparapu: The second one was had that happened about nine years ago, when I was writing a paper and the paper was about how common earth like planets in our galaxy. And I found, I did some calculation, I found that they are more than what I expected, and I literally jumped out of my chair, like, literally. I was like, “This can't be possible. I'm standing in front of history that's happening right now that we will for the first time in our life, we know, how common are Earth-like planets.” And and that really motivated me to study. You know, how do we find even more out? Okay, if they're so common, where can we find this life? And that's really motivated me to pursue more and more opportunities. And that's why I'm at NASA Goddard, because this is where the missions happen. This is where we try to find life on other planets. And that's, that's my second gravity assist, I would say.

Jim Green: Well, that's fantastic. You know, your excitement about the science and the things that you learn propel you to keep going and accelerate you. And hopefully, you will be the one to announce that we have found life beyond Earth.

Ravi Kopparapu: (laughs) Oh, I hope you will be with me at that time, Jim.

Jim Green: I'll at least be able to interview you. (laughs) Well, Ravi, thanks so much for joining me for this fantastic look at finding habitable worlds in other solar systems.

Ravi Kopparapu: Oh, thank you so much, Jim. This is wonderful. Thank you.

Jim Green: Well, join me next time as we continue our journey to look under the hood at NASA and see how we do what we do. I'm Jim Green, and this is your Gravity Assist.


Credits
Lead producer: Elizabeth Landau
Audio engineer: Manny Cooper
Last Updated: Apr 8, 2022
Editor: Gary Daines

Source: https://www.nasa.gov/mediacast/gravity-assist-do-other-planets-make-pollution-with-ravi-kopparapu
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Odp: [NASA Gravity Assist] : Season 5
« Odpowiedź #47 dnia: Sierpień 13, 2023, 07:29 »
Poprzez badanie przejawów życia organicznego głęboko pod grubą pokrywą lodową w ziemskich warunkach można spekulować nad możliwościami istnienia życia na wodnych Księżycach w Układzie słonecznym.
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Catherine Walker: So a few things, I guess, out in the solar system, we're working on a project to try to look at how life might have evolved in Europa’s ocean, looking at sort of how you might expect things to evolve with the lack of sunlight, which is usually what we think of here on Earth, we think of “oh, you need photosynthesis and sunlight and water to survive.” And obviously, they have enough water on Europa, but none of those other things, and a lot of radiation, which we don't have here on Earth. And so we have to sort of rethink how we think about how life forms and how it maintains itself. So we're looking at that.

Gravity Assist: Walking on Broken Ice, with Catherine Walker (1)
Apr 22, 2022


NASA management fellow and visiting scientist Catherine Walker is seen in October 2014 on the McMurdo Ice Shelf in Antarctica, in front of Mount Erebus, an active volcano (in the background). Credits: Jacob Buffo/Dartmouth College

An ice shelf collapsed in East Antarctica in March 2022, concerning scientists who track melting glaciers, sea level rise, and other effects of climate change. Catherine Walker, a visiting scientist at NASA’s Goddard Space Flight Center, uses NASA satellite data to look at the progression of events like this one to understand how large ice structures collapse. She is also looking at Jupiter’s moon Europa and what kind of life might be able to survive under the ice there. Learn about her Antarctica adventures and her scientific journey on this episode of Gravity Assist.

Jim Green: On Earth Day, we're going to talk about water and ice.

Catherine Walker: The ice sheets of the Earth, Greenland and Antarctica are sort of two of the biggest uncertainties, in future climate projections.

Jim Green: Hi, I'm Jim Green, and this Gravity Assist, NASA’s interplanetary talk show. We’re going to explore the inside workings of NASA and meet fascinating people who make space missions happen.

Jim Green: I'm here with Catherine Walker, and she is a management fellow at NASA Headquarters and a visiting scientist at the Goddard Space Flight Center. Catherine has done fantastic research, looking at the oceans and ice on Earth, as well as other planetary bodies. Welcome, Catherine, to Gravity Assist.

Catherine Walker: Thanks. It's very exciting to be here. (laughs)

Jim Green: Well, you know, I'm really delighted to talk to you about, you know, one of my favorite topics, which is water in whatever form we can get it in. And indeed, you've gotten interested in studying oceans and glaciers. How did that happen?

Catherine Walker: Early in my life, we lived near the beach. And so we saw the ocean all the time. And I was sort of just captured by its power, because it, living right on the coast, you get a lot of storm damage and things like that. And other days, you'd look in, it's flat, calm. And so it was just sort of this dynamic system that you can see moving and doing things on the Earth on really short timescales. And so you know, on a human level, you just want to understand that.

Catherine Walker: Early on in my career, though, I was a geologist. And eventually, that turned into looking at planetary surfaces, things like Mars and the Moon, early in my undergrad career. And then eventually, there was a newspaper article about Cassini had seen Enceladus. And I learned that there were these planets that were made entirely of ice, which, you know, in some, in some sort of thought process that is similar to rock when it's that far in the solar system. And so I ended up looking at ice on planetary scales, and then coming back down to Earth and saying, “Hey, what does it do here on Earth?” And so I sort of did a roundabout way of becoming a glaciologist.

Jim Green: Well, when you go out in the field, you've been actually looking at glaciers. What are you trying to do when you go out and, you know, explore?

Catherine Walker: Yeah, that's a great question. And I guess there's multiple answers. The first, first and sort of foremost, when we go out to look at glaciers in my research anyway, we're looking for how, right at that point where the ocean and ice meet. So these are called marine terminating glaciers. These exist in Greenland, they exist in Alaska, and obviously, Antarctica, which is surrounded by the ocean. And so we look at how the ocean and ice sort of interactions happen over time, and how the warming ocean since that's the sort of big sink of heat here on Earth, how that changes and how that then affects our ice caps and ice sheets on the Earth. And so we go out there and measure how the ice has, is shrinking, mostly, sometimes growing, but usually using airborne science and satellites. And then some, you know, ground measurements that we go out and measure things like radar, measurements of thickness and things like that. Another answer, though, is we use Earth's ice sheets to better understand ice on other planets and how it interacts with oceans or water there. And so a lot of the times we go out with the intention of sort of measuring these things, not just for the processes here on Earth, but trying to understand the physics of it so we can sort of take that knowledge and move it to other planets.

Jim Green: Didn't we just have a big glacial disconnection, where a big ice sheet was broken off? And that and that's because it just got thinner and thinner and broke off? What do we know about that? And how large was that glacier that broke apart?

Catherine Walker: Yeah, the Conger Ice Shelf, which was in East Antarctica, completely collapsed, which is not totally unprecedented. There have been a few ice shelf collapses in West Antarctica, which is generally thought of as the warmer part of Antarctica. It's sort of hard to think about Antarctica being warm at all.

Jim Green: (laughs)

Catherine Walker: But the western side is generally what we think about when we think about these melting glaciers and ice sheets that we that we hear about in the news.

Catherine Walker: East Antarctica, on the other hand, scientists generally think of as relatively stable. We sort of have that as our bank of, of freshwater ice on the Earth. It's very cold, it's very slow. It's like the definition of glacial pace over there. Doesn't really do much. And so we were sort of thinking that it of that place is stable. But yeah, a couple of weeks ago, a small ice shelf called Conger Ice Shelf, which is about 1,200 square kilometers in area. We were watching it over a few months now. But now that we have, now that we know we collapsed, we can use that satellite record to look backwards in time and see what it was doing over time. And we could see that it was just getting thinner and thinner, as the ocean warmed it.

Catherine Walker: And eventually, something called an atmospheric river arrived in Antarctica in early March. And what an atmospheric river is, it's a big weather event that sort of brings in heat and moisture from the tropics, which is not unprecedented, but very rare in Antarctica, and you get these temperatures and winds and waves that came in with this, with this sort of low pressure event that turned it into this, sort of, “too much to handle” for this thinning ice shelf, so it collapsed.

Jim Green: Wow. Well, what happens to it then? Does it eventually completely get consumed by the ocean that it swims in and then the ocean rises?

Catherine Walker: Yeah, so the ice shelf, as it broke up, it made a few big icebergs that are now floating off into the southern ocean and they'll go on to melt probably within a few months or a year. You know, sort of trailing freshwater and changing the nutrient amounts for, for ecosystems down there as they go. The other sort of, I guess, concern that we have is now that that ice shelf has come away from the coast, there's nothing holding back the glaciers behind it. And that's usually what we worry about when we talk about sea level rise. When these ice shelves around edges of the continent collapse, they can release all this ice uphill, to slide more quickly into the ocean, and that's what will cause sea level rise.

Jim Green: Wow. Well, how does your research fit into the bigger picture of climate change?

Catherine Walker: Yeah, that's a great question. So the ice sheets of the Earth, Greenland and Antarctica, are sort of two of the biggest uncertainties, in future climate projections and in particular projections, for sea level rise, timing and volume, I guess. So when we think about how, you know, studying ice and ocean interactions, how those inform on future climate predictions, we usually think about how those will affect sea level as we know it.

Catherine Walker: And one of the biggest unknowns right now anyway, in glacier science is how quickly something can collapse, which seems like a big, fairly easy question to answer, like, you know, if you look at the Cliffs of Dover, for example, why aren't those collapsing? How are they holding themselves up? You know, it's not a miracle. That sort of material, rocky material has a strength to it, it can hold itself up to a certain degree, and then you get these little calving off periods.

Catherine Walker: Same thing happens for ice. We just watch things like this recent Conger collapse, Conger Ice Shelf collapse. We use those events to study how strong ice is. And then we can study how quickly these retreats can happen, and how then how quickly sea level rise will happen. So yeah, that's how those two sort of feed into our expectations for the future.

Jim Green: Well, I heard that you also had a robot in Antarctica. What were you doing down there? And what was that project all about?

Catherine Walker: Yeah. So this is a nice tie-in to this sort of cross between Earth science and planetary science. So when I was a postdoc researcher at Georgia Tech, I was working on a project looking at the ice-ocean interface. So when we think about these ice shelves in Antarctica, it's just this big slab of ice that's about, can be up to 100 meters thick. So we're talking substantial ice cover. So you have this ocean underneath that is completely removed from sunlight, or really any current activity or anything like that.

Catherine Walker: It's just sort of this cavity underneath ice. And so we were down there, trying to study what's happening right at that interface between the ocean and the ice underneath, and what sort of life lives under there. And so, you know, how else do you do that, but you send down a submersible vehicle. Unfortunately, people couldn't go in it, which would have been fun, but we couldn't go. It was just a little, basically a camera and some oceanographic instruments. And we sent it down. It sort of looked like a torpedo.

Catherine Walker: And we sent it down through a hole in the ice, and it swam around down there. And it was really neat, because I guess as a, as a glaciologist, or an ice person, I was sort of just there to see what the shape of the ice looked like and what how much was melting and things like that. But once we got to the sea floor, we could actually see these, you know, anemones and starfish and like something I thought was a lobster but it was just a giant shrimp. It was it was really cool. And you know, just thinking of how these things live down there with no sunlight. And no, you know, no nutrient source or anything like that was, was sort of super cool to see. Just sort of proved the point of like, you never know what you're going to find when you go exploring.

Jim Green: That's right. And you always have to look. So yeah, so these interfaces between the ice and the water are really important. And I'm just delighted that you were continuing to find life in those interfaces, because the Earth is not the only planet that has those kinds of interfaces. But before we talk about things out in the solar system, I want to ask you about some memorable stories that you may have had in the Antarctic.

Catherine Walker: Sure. So one of the most memorable things that happened to me when I was there. So maybe this is, you know, not clear to anyone who hasn't been there, maybe. And I didn't know this before I got there. But so GPS doesn't work near the poles, just because it sort of searches and searches for north or south but can't find it. So you can't use that to figure out where you are. And since we had this robot underneath the ice, we also couldn't visually see it, because it's covered, you know, there's ice, but then there's lots of snow on top of it. So you can't see through the ice or anything.

Catherine Walker: And so to figure out where the robot was below us, when we were standing on top of the ice, we had these giant magnetic rings that we had to hold and wear earphones. And when the magnetic pinger on the robot was below us, it would make a buzz in our, in our ears. And so we were sort of wandering around this great big area on the ice, hoping to hear a ping to figure out where the robot was. And I saw this sort of hill, and I was like, “Oh, I'm gonna go that way.” And so I started walking up. And I knew from my experience in my PhD that usually those hills meant that this was the transition between sea ice and an ice shelf. It's just windblown snow, that sort of making that transition. So sea ice is not permanent ice, it's, it's frozen out of the ocean in the winter.

Catherine Walker: And so that's what I had been walking on. And I was like, “I'm gonna go up onto the ice shelf, which is where we thought the robot was underneath.” And so knowing my significant experience looking at satellite images of the area, I said, “Oh, I didn't realize they were attached to each other, the sea ice and the ice shelf.” But in my eye at the time, I was like, “No, it looks connected, I'm going to walk up this hill.” And so I walked up, and suddenly I dropped up to my armpits, basically, into the snow. And I had to hoist myself out.

Catherine Walker: And I grabbed the, the magnetic ring. I was like, “Oh, my God, what happened?” and I looked back down, to where I popped out of, and there was this giant opening. And it was basically it wasn't connected, I was right, from my satellite experience. There was about a 20-meter drop down into the ocean from there, and so survived that. (laughs) But that teaches you to trust your intuition and not your visual sight. (laughs)

Jim Green: Wow. Yeah, that could have been dangerous. I'm so glad you survived that, indeed. (laughs)

Jim Green: So as our ice sheets begin to melt, and that's going to continue to happen. Is there a process for which they can come back?

Catherine Walker: That's a great question, one that's sort of goes to our hope for the for the future, right? Because we hear a lot of news reports and things that say, Hey, you know, expect the worst. Another ice sheet or an ice other ice shelf has collapsed? Oh, no. Which it is sad to watch them collapse, of course. And there is a large amount of evidence that the ice on Earth is shrinking, of course, but one of the things that we don't know, aside from some of the stuff I talked about before about how it's holding itself together, we also don't know, you know, as more ice melts into the ocean, we don't know how all that freshwater getting added to the system will change the ocean currents in the ocean system as well.

Catherine Walker: And so most of what we think about in terms of how If we expect things to change in the in the future is set up based on how things work now. But we don't exactly know, you know, if you add a whole bunch of, you know, say all of West Antarctica disintegrated, which hopefully it doesn't. But even if it all did, you know, what would that actually do to the ocean? And it might even stop itself, it might change current systems and things like that to either slow or stop the process from continuing.

Catherine Walker: So we don't know a lot of those natural feedbacks that might actually kick in to help, you know, reverse the, the process. They're also, you know, a lot of, I guess geoengineering ideas about how to sort of enhance the albedo of the earth and reflect more sunlight back up. You know, the Earth has a natural process in sea ice formation that does that already. But if we can sort of prop up that process and cool things down maybe, there are a lot of ideas like that circulating as well. So it's not all it's not all bad news.
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Gravity Assist: Walking on Broken Ice, with Catherine Walker (2)


Catherine Walker in Antarctica in 2014. Credits: Jacob Buffo/Dartmouth College

Jim Green: Well, your experience on Earth about oceans and ice, and we're finding those kinds of objects out in the solar system. What are the top icy moons that you're interested in when you when you think about these, these wonderful phenomena?

Catherine Walker: Well, the first one that comes to mind, of course, is Europa. It’s sort of this perfect, or seemingly perfect laboratory, for life to maybe evolve if it's there. It's got a liquid ocean underneath a nearly pure water ice ice shell. We can see in the cracks on the surface, that there's a lot of salts and things that you might expect from an ocean very similar to ours. So that one's sort of a pretty obvious one.

Catherine Walker: There's also Enceladus which is a moon of Saturn. (laughs) Which also likely has a, well, it at least has a south polar ocean if not a global ocean, also a pure water ice ice shell. And there's other ones I guess, like, you know, Ganymede or Callisto, which are older well and Ganymede, it's much larger. But a lot of these places that maybe people don't think about all the time, but I think it's hard for us to imagine an ocean below any sort of solid crust, but there's a lot of these places. a lot of these icy moons out there that, you know, look very solid to us and are expected to be solid because they're sitting out in the middle of, you know, way-below-freezing solar system, but they actually have a lot of water. And you know, comparatively Earth is pretty dry compared to some of these places. So it's exciting.

Jim Green: It sounds to me like our new view of the solar system is that the solar system is a soggy place.

Catherine Walker: (laughs) It’s a good way to put it.

Jim Green: (laughs) Well, what projects are you currently working on now?

Catherine Walker: So a few things, I guess, out in the solar system, we're working on a project to try to look at how life might have evolved in Europa’s ocean, looking at sort of how you might expect things to evolve with the lack of sunlight, which is usually what we think of here on Earth, we think of “oh, you need photosynthesis and sunlight and water to survive.” And obviously, they have enough water on Europa, but none of those other things, and a lot of radiation, which we don't have here on Earth. And so we have to sort of rethink how we think about how life forms and how it maintains itself. So we're looking at that.

Catherine Walker: Another project I'm working on is looking at that Conger Ice Shelf that we were talking about earlier, how that is going to affect that particular region of Antarctica, in the near term and long term. And another project that I'm working on now is just looking at sort of how to how to better I guess, observe high mountain regions. The ICESAT spacecraft, it's a really great spacecraft to look at flat things which is good for ice sheets, for example, but it doesn't do so well on things that are highly sloped. For example, like mountain regions, or quickly changing glaciers so at the edges of the ice, you get these places that are highly cracked and are moving really quickly and unfortunately ICESAT doesn't do as well there. So we're looking at designing new technologies to try to figure out how to do that better.

Jim Green: In thinking about the possibility of life underneath the icy crust of Europa, how could they possibly survive? And what would they look like?

Catherine Walker: That's a great question. And I'm sure a lot of people have a lot of answers. But one of the things we can think about on Earth is that, you know, a few decades ago, I think the general idea of life on Earth was, you need sunlight, you need water, you need certain number of nutrients. But, you know, over, over the last few decades, even this is new, sort of science, you know, we know now, things called extremophiles have been found things that live in, you know, some of the hottest places, the bottom the ocean at those vents, those sort of mid-Atlantic ridge vents, never would have thought of that before, you know, a few decades ago, that that would be a place that anybody would like to live.

Catherine Walker  But, you know, we found organisms that not only don't need sunlight, but then they can also live with these high-high-heat places in the darkness, and things like that. And we also found underneath the ice sheets on Earth, you know, we've drilled a really deep hole in the ice in the middle of the ice sheet in Antarctica, you know, 1,200 meters down, found a pocket of water, and there was literally a shrimp in there living — you know, no sunlight, no, nothing that we think of as nutrients. But he was living down there, probably with a family. And so there's the sources of energy and things that we don't, we still don't know all about. And so, you know, I imagine at Europa, there's very similar sort of resourceful organisms that can figure out how to survive and how to sort of turn that, any energy they can get into something they can live on.

Jim Green: Yeah, that would be fantastic, if we could find life in the ocean of Europa. It would tell us that, that life is a pretty universal thing, and perhaps all over our galaxy.

Jim Green: Well, Catherine, I always like to ask my guests to tell me what was the person, place or event that has gotten them so excited about being the scientist they are today. And I call that event a gravity assist. So Catherine, what was your gravity assist?

Catherine Walker: So I guess I have a two-fold gravity assist, I think I like to think of it as maybe my exit from low-Earth orbit. And then the next one was a, you know, slingshot around the moon or something like that. So the first one that I can think of, that sort of got me into getting interested in being a scientist, was, this is gonna sound silly, but I saw the movie Apollo 13, when I was about 10 years old.

Catherine Walker: I told my parents, I said, “I'm gonna be an astronaut,” which is basically the same as most 10 year olds, probably. And then unlike most other folks, I think I'd never let that go. As I continued through my career, I said, “Oh, you know, I liked the ocean. I like geology.” And I said, “hey, those things would actually help me be an astronaut someday.” And so I never gave that up. Later in my career, once I was getting through college and things like that, I got an internship at the University of New Hampshire with a scientist named Antoinette Galvin, and she was the PI on the, one of the instruments on the STEREO mission. And I got a summer internship there. I was excited. It was close to home.

Catherine Walker: And it was exciting because it was an actual mission at NASA, and I was, you know, finally working on a NASA thing. And she was very kind to me, I'd never had any sort of spacecraft experience before. So, you know, it was perfectly reasonable if she was sort of like, “Hey, do this summer project, and then you're done.” But she, you know, she was super helpful and encouraging. And she kept me on after the summer. She said, “Would you like to keep working with us, we'd love to have you on the team.” And she was just one of those people that didn't have to be that nice. But she was and she was interested, I guess, in you know, sort of paying it forward in the in the field. And so that really got me started at NASA. And got me even more excited about being involved in stuff like this. So yeah, she's, she's the person that sort of pushed me forward.

Jim Green: That's fantastic. Well, Catherine, thanks so much for joining me and talking about a fantastic look at water, not only as liquid but as ice.

Catherine Walker: You're welcome. Thanks so much for having me.

Jim Green: Well, join me next time as we continue our journey to look under the hood at NASA and see how we do what we do. I'm Jim Green, and this is your Gravity Assist.


Credits
Lead producer: Elizabeth Landau
Audio engineer: Manny Cooper
Last Updated: Apr 25, 2022
Editor: Gary Daines

Source: https://www.nasa.gov/mediacast/gravity-assist-walking-on-broken-ice-with-catherine-walker
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Odp: [NASA Gravity Assist] : Season 5
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Odp: [NASA Gravity Assist] : Season 5
« Odpowiedź #49 dnia: Sierpień 20, 2023, 07:11 »
Jak wyhodowano Arabidopsis thaliana z użyciem księżycowego regolitu.
Cytuj
Anna-Lisa Paul: So the samples actually came from three locations: from Apollo 11, Apollo 12, and Apollo 17. And so the three sites that the astronauts worked on had different characteristics. All of the materials are what are called basaltic. And so most of them were sort of ground up basalt, lava kind of, kind of materials. But each of the sites were exposed to the surface for different periods of time. And what that means is that the regolith has what's called different levels of maturity.

Gravity Assist: How to Grow Food on the Moon (1)
May 13, 2022


Researchers at the University of Florida successfully grew plants in lunar regolith brought back during three different Apollo missions. In this photo, a scientist places a plant grown during the experiment in a vial for eventual genetic analysis. Credits: UF/IFAS photo by Tyler Jones

Space botanists are working on strategies to grow crops on the lunar surface, as NASA makes strides toward sending astronauts to the Moon through the Artemis program. A team of scientists at the University of Florida successfully grew small plants in lunar soil brought back during three different Apollo missions. How did they do it, and what does it mean for the future of space exploration? Dr. Anna-Lisa Paul explains.

Jim Green: Can we grow food on the Moon? This may end up being a fundamental question of survival in space. Let's talk to a space botanist.

Anna-Lisa Paul The only way that humans can be explorers is if we take our plants with us.

Jim Green: Hi, I'm Jim Green, and this Gravity Assist, NASA’s interplanetary talk show. We’re going to explore the inside workings of NASA and meet fascinating people who make space missions happen.

Jim Green: I'm here with Dr. Anna-Lisa Paul. And she is the professor of horticultural sciences at the University of Florida's Institute for Food and Agricultural Sciences. And she is the director of the University of Florida's Interdisciplinary Center for Biotechnological Research.

Jim Green: Dr. Paul and her colleagues just published a fantastic new study. And this study describes how plants grow in samples of lunar soil brought back by astronauts in the Apollo program. Wow! I can't wait to hear how this was pulled off. So welcome Anna-Lisa to Gravity Assist.

Anna-Lisa Paul: Thank you. Thank you very much. Pleasure to be here.

Jim Green: The paper that's out now is really exciting, because it tells us that we now have options of going to the Moon and being able to live and work on a planetary surface for long periods of time, because we have an aspect of sustainability by growing food. So is this project something you've been wanting to do for a long time?

Anna-Lisa Paul: Absolutely. This is a project that has been sort of on my, and my colleague, Rob Ferl’s radar, for decades, because when you think about if the only way that we can humans can be explorers, is if we take our plants with us. Plants are what allows us to be explorers, they can go past the limits of a picnic basket. So for us who work in space biology, we wanted to know if when we get to a new surface, can we use the resources that are already existing there, the in situ resources? And for the Moon, that would be the regolith, which can be used as the dirt to grow plants.

Two scientists, wearing white lab coats gaze into several large clear boxes, each containing two smaller boxes of six to seven small dark objects. This image in bathed in pink light.



University of Florida researchers Rob Ferl, left, and Anna-Lisa Paul, examine a collection of culture plates – some filled with lunar regolith, some with simulated regolith -- under LED lights. Credits: UF/IFAS photo by Tyler Jones

Jim Green: Well, how hard was it to get your hands on these samples, the original samples from the Apollo program?

Anna-Lisa Paul: It was pretty hard to get those. You have to remember, they're a national treasure, they are completely irreplaceable in their original form. And so when you have a couple of biologists who go to an institution of higher archiving from NASA of the original Apollo samples, and you say, “Yes, we’d please like to have some of your precious materials and get them all messy and grow plants in them!” They say, “Excuse me, you want to do what?” And so it took three different iterations of proposals, which also include a ton of background information and tests with lunar simulants before we could convince the powers that be that, yes, yes, we will take good care of them. We're good representatives of what science can be done, and they let us have some. In fact, they let us have 12 grams.

Jim Green: 12 grams. I know that doesn't sound a lot.

Jim Green: Well, what's really amazing to me when we think about plants growing in regolith is, is what regolith is. You know, it's really ground up rock, that comes from impacts over and over, billions of years of impacts on the Moon, blasting everything apart. And when you look at the regolith, this ground-up rock, in a microscope, it's got all these shards. It's, it's very sharp, which is one of the reasons why we're worried about this regolith, when humans walk around in spacesuits, getting into their lungs.

Jim Green: And so the concept that we can actually grow plants in it, was really amazing. So, tell us about these lunar samples. Did they come from one location or many locations?

Anna-Lisa Paul: So the samples actually came from three locations: from Apollo 11, Apollo 12, and Apollo 17. And so the three sites that the astronauts worked on had different characteristics. All of the materials are what are called basaltic. And so most of them were sort of ground up basalt, lava kind of, kind of materials. But each of the sites were exposed to the surface for different periods of time. And what that means is that the regolith has what's called different levels of maturity.

Anna-Lisa Paul And so the regolith from the Apollo 11 site, for instance, was more mature. That means it has been exposed to the cosmic wind for longer. So the particles are smaller, the edges are sharper. The Apollo 17 samples were particularly interesting in that it, the type we got was actually a compendium of materials from all over the site, because it was the dirt, if you will, that got caught underneath a bumper on the lunar rover.

Anna-Lisa Paul: And as, as they were leaving, Harrison Schmidt said, wow, there's a whole bunch of stuff here. Let's not let that go to waste. And he dumped it all into a bag and it came back to Earth for, for us eventually.

Jim Green: Wow, that's fantastic. So tell me about the experiment. If you only had a little bit from each of these sites, how are you going to really grow plants in them?

Anna-Lisa Paul: So we used the plant called Arabidopsis thaliana. And the cool thing about Arabidopsis is, in addition to being very well characterized at the genomic level, and gene level, it’s small, it's really small, and you can actually grow an almost full size plant in a single gram of material.

Jim Green: Wow.

Anna-Lisa Paul: So what we did is we had these specialized plates that are normally used for cell culture, there are only about 12 millimeters across -- each one of these little pots, if you will. And we put the regolith inside these little pots and then planted seeds on top of them, watered them from below and: instant lunar garden.

Jim Green: Wow, that's unbelievable. So you had a regimen of just adding water to the to the seed and that’s all it took?

Anna-Lisa Paul: It took a little bit of nutrients, too.

Jim Green: Okay.

Anna-Lisa Paul: And so how it was set up was a little plug of material called rockwool, which is essentially just spun lava rocks, that makes a sponge, and then the regolith goes on top of that little sponge. And so now the sponge acts as a capillary wick to get liquids up into the regolith. So the nutrient solution that went down into the base of the tray got wicked up into the regolith, and it was essentially watered from below.

Jim Green: Wow, interesting. So then it's easy to think about how that could work by developing a greenhouse with these kind of attributes on the Moon and then just bringing in the regolith. 

Jim Green: So at the end of the experiment, did you then take apart the regolith to see how the roots grew with in the planter?

Anna-Lisa Paul: We did. Because we planted more than just a single seed at first, when we thinned the little tiny seedlings away to just leave a single plant in each one of those little micro pots, we also got to look at the roots there. And so we could see that the plants that were growing in the simulant, it's called this JSC-1A, it's a type of volcanic ash that’s mined on Earth, that's what we use as our control.

Anna-Lisa Paul: Compared to the lunar regolith, the JSC-1 simulants were nice and long and tapered and looked very healthy, but the roots that were growing in the regolith were kind of scrunched up and they weren't quite as healthy looking. Nonetheless, once they grew, you could get decent looking plants growing in the regolith. And just to look at them with your eye, they'd look a little smaller than the ones in the controls. But the real key was when you ground them up, and you look at what genes are being expressed.

Jim Green: Now, as you said, you use simulant, which means we think we've been able to develop a process that can make lunar-like regolith without bringing it from the Moon. But as you said, already, there's some differences between that simulant and what the real regolith looks like. But that's an important control factor. That also helps us figure out if we're making those simulants correctly or not.

Anna-Lisa Paul: Yup.

Jim Green: So what did you find out?

Anna-Lisa Paul: So when you take a look at the controls, I have to say, any experiment is only as good as your control, right?

Jim Green: Right.

Anna-Lisa Paul: And so, the control material really did look a lot like the lunar regolith. It behaved a lot like the lunar regolith in the way it absorbed water and the way that it kind of just settled into the pots and everything. But when we’ve looked at the example of even if you take two plants that looked very similar between the control and the lunar regolith grown, we found that the kind of genes that the plants expressed different from the ones that were in the control were mostly genes that are associated with metal stress, like heavy metals, or salts, or what we call oxidative stress.

Jim Green: Oooh!

Anna-Lisa Paul: Even though those materials per se weren't necessarily in those regoliths. It's not like the regoliths were actually salty. But the plants perceived the type of stress they were seeing in that material as salt stress, as metal stress. And so that was an interesting insight that they were changing the way they express their genes to adapt to that new and novel environment.

Jim Green: Oooh. So this is really critical to understand. Because once you understand that, there may be processes and procedures that you could do that alleviate that plant stress that allows them on, on the real example, on the Moon in a greenhouse, to then really flourish better than even what you did in the laboratory.

Anna-Lisa Paul: That's exactly right. That's button on. So the Arabidopsis is really closely related to some of your favorite vegetables, like, say, broccoli. And we know that if we want our broccoli plants or kale plants to be healthy and growing in the lunar regolith, in a greenhouse, we know that we'll have to mitigate some of these kind of stress responses. We can do that in two ways. You can engineer their environment by mitigating perhaps some of the materials that are in the regolith, you can also engineer the plants themselves. And you can make them less sensitive to some of these aspects. And so instead of putting their energy into the stress response, they put that energy into making more broccoli.

Jim Green: Right! That's really a, just a huge advance. By doing this on the Moon, we're going to also learn the processes and procedures we'll have to do on Mars. So that will be really critical. S o I really dearly love this idea. So if I was in the lab, and we were done with the experiment, we were taking them apart and looking at the roots, I might be tempted to eat one of these. Did anyone do that?

Anna-Lisa Paul: Well, we didn't eat any of those because, think about it: they’re a very small and very precious resource that we wanted to save to do the biochemical analyses. You could eat Arabidopsis. People have eaten them before, but it's not exactly something that would be good in a salad.

Jim Green: (laughs) So not so tasty after all.

Jim Green: I can imagine walking into the lab, when it, when you had started these plants growing. And the first time you realized this was gonna work. What was that like?

Anna-Lisa Paul: Oh, so the preparation that went into this experiment is extraordinary. All the background, all the setup, everything, the way we planted them, every aspect of it was complex. And so then at the end, Rob, and I walk out to our secure growth chamber where these things are going to go, we set them all up under their pink LED lighting systems that will keep them going. And we closed the door and we thought, all right, three days, things should be germinating in three days. Well, two days later, we walked back in there just to kind of check, and we’re looking down at all those plates. And every single one had germinating seeds in it.
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« Odpowiedź #50 dnia: Sierpień 20, 2023, 07:11 »
Gravity Assist: How to Grow Food on the Moon (2)


University of Florida researchers Anna-Lisa Paul and Rob Ferl are seen at the Haughton Crater impact site in northern Canada. NASA uses this crater for Moon and Mars analog research. Credits: Pascal Lee

Jim Green: Wow!

Anna-Lisa Paul: The controls, the lunar samples, everything was germinating. There's this tiny nascent greenness, every single one, and it just took our breath away. It worked. It really worked. How cool is that?

Jim Green: You know, it reminds me of the theme in the movie “The Martian,” where Mark Watney goes over to his potato plant that is now growing for the very first time, touches the leaf, and says “hello.”

Anna-Lisa Paul: Yes, exactly.

Jim Green: Wow, that's great. I can also imagine that this will enable you to think of the next best experiment to do. Have you been thinking about and formulating your next steps?

Anna-Lisa Paul: Oh, absolutely. One of the things that would be wonderful to do is to have additional replicates for this. With four grams each from each site, we could obviously only have four replicates of one individual plant each. Being able to have a larger volume of material so that we could try different kinds of mitigations. All of the samples had to be treated with the same nutrient solution for instance. And so if we had enough material, we could also change the variables of what kind of nutrients we did. Are there other ways to mitigate some of the effects of the regolith? Those are the kinds of things you can only do with more material.

Jim Green: I understand you've done some field tests in far off places here on Earth.

Anna-Lisa Paul: Yeah, so I've definitely had the privilege to explore some very interesting, what we call analog sites, in the in the world. The first step was, Rob Ferl and I went to the far north Canadian Arctic at an old impact site, called the Haughton Crater on Devon Island. And one of the reasons we went to Devon Island was to practice utilizing in situ resources in a greenhouse that was growing there.

Anna-Lisa Paul: And so we collected these, what we call, brecciated materials from this old impact crater, which was 20-plus miles across, that was very lunar looking. And we’ve use some of those materials in the greenhouse. We also used the JSC-1 simulant in the greenhouse, along with other kinds of materials and asked: Can we populate a greenhouse substrate with these kinds of non-traditional growth substrates to create materials and crops over the winter?

Jim Green: So what did you find out when you did that?

Anna-Lisa Paul: Well, we find that they actually like growing in the JSC-1 simulant a little better than they liked growing in the brecciated materials we dug out of the crater. (laughs) And part of that is because a lot of the materials have different types of chemicals in them that are actually in some ways more analogous to what it would be on Mars. Whereas the lunar regolith is pretty much just devoid of everything, the Martian regolith i, looks to be, although nobody's brought any back, it looks to be high in, say, perchlorates and other kinds of reactive chemicals that would have to be, again, ameliorated before you could grow plants in it. But you'd be have to be able to use the materials from where you land.

Jim Green: So on the Moon, I imagine we're going to have a greenhouse, but can we really grow these out in the vacuum of space?

Anna-Lisa Paul: Well, they would have to have a greenhouse just like a human would have to have a greenhouse because that there's no atmosphere on the surface of the Moon. So all of the plant growth would be being carried on in some kind of greenhouse or other sort of enclosed habitat along with its attending humans.

Jim Green: Well, you know, another part about that, that I like, is the fact that these plants as they grow will smell wonderful. And you get not only this the green of the plant, you also get the smells, and it's gotta remind astronauts of home.

Anna-Lisa Paul: That that is so true. And I have actually a personal experience that, that speaks to that very well. I mentioned the work that I've done in the high Canadian Arctic. Well, I've also been down in Antarctica for a while. And again, working on a greenhouse that was essentially called the Future Exploration Greenhouse, part of the Eden ISS project, that was an analogue of what you might find on the Moon or Mars.

Anna-Lisa Paul: I was down there for several days, and the weather was just horrible, and nobody could go outside, it was absolutely impossible, and everything was dark, and bleak and awful. And then, when the weather started to clear just a little bit, we went out to the greenhouse for the first time on that trip and walked into the door, and you're met by the smells and the moisture and the greenness. And it was like, all of the stress evaporated from all of us. And we were home for a bit. And I can well imagine it would be like that for an astronaut. And you can't underestimate how powerful, how powerful a plant can be from that context, as well as the fact that it cleans your air and gives you clean water and gives you food. It also gives you something spiritual.

Jim Green: Very nice.

Jim Green: Well, Anna-Lisa, I always like to ask my guests to tell me what that person place or event was that got them so excited about being in the sciences that they are today. And I call that event, a gravity assist. So Anna-Lisa, what was your gravity assist?

Anna-Lisa Paul: Well, gravity assist for me has been people, and the very first person was my mom. And I can remember quite keenly as a little kid asking my mother about how something worked. And she would say, “I don't know, let's find out.” And so it was always this, this journey of discovery. I would be given science books as a small kid, even though I couldn't quite read them at that level. And we'd go through as a family trying to figure out how to do the kind of experiments we could do in the backyard. And I got really interested in plants, because plants were the only things that were taking the energy that comes into the planet, and turning it into stuff that we needed.

Anna-Lisa Paul: So as I got older and started wondering about how plants work, it kept taking me one step after another until I decided I'd like to understand how plants respond to novel environments, and the most novel environment out there is space.

Jim Green: Wow, fantastic. That, that's a wonderful environment to be in, where you can work with your parents on a journey of discovery, and then realize how you can make a wonderful career out of it. So thanks so much for telling us about this really fundamental and exciting research.

Anna-Lisa Paul: I'm pretty lucky. Thanks.

Jim Green: You're very, very welcome. Well, next time, we're going to talk to a researcher at the Kennedy Space Center, who also works on growing plants in space. But in this case, it's all about astronauts growing them on the space station. You won't want to miss that. I'm Jim Green, and this is your Gravity Assist.


Credits
Lead producer: Elizabeth Landau
Audio engineer: Manny Cooper
Last Updated: May 13, 2022
Editor: Gary Daines

Source: https://www.nasa.gov/mediacast/gravity-assist-how-to-grow-food-on-the-moon
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Odp: [NASA Gravity Assist] : Season 5
« Odpowiedź #51 dnia: Sierpień 27, 2023, 11:25 »
O różnych aspektach hodowli roślin w kosmosie.
Podczas pierwszego lotu duńskiego astronauty  jeden z 10. z eksperymentów polegał na stworzeniu sztucznego ekosystemu w małym pojemniku, w którym rośliny i mikroorganizmy mogą żyć i tworzyć żywność dla astronautów.
Podczas obecnego lotu Duńczyka wśród 10. narodowych eksperymentów nie ma podobnego.
Czy podczas następnych krótkich lotów astronautów ESA znajdzie się miejsce na biologiczne eksperymenty?

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Christina Johnson: One of those workhorse plants that can grow really well is mizuna, It's a mustard plant. And that one's been growing in pretty much every platform since we started growing plants in space. It grew on Mir, it grew on the shuttle, it grows on the space station. We've had many successful harvests with it and in many different kinds of plant hardware. That one's, that one's kind of our go to for, for testing to it's like okay, well this one work? Let's try it with mizuna. Mizuna does great, okay. Let's try it with something else. So mizuna one of those that just keeps coming up. And astronauts love to eat it too because it has this mustardy flavor. It's not a boring green.

Gravity Assist: What Will We Eat on Mars? (1)
May 20, 2022


Plants growing in the Veggie plant growth chamber on the International Space Station. Credits: NASA/ISS

Astronauts on the International Space Station have been conducting experiments to grow food, including peppers and radishes. Christina Johnson, a NASA postdoc fellow at NASA's Kennedy Space Center in Florida, has been working on a variety of techniques to grow food in space. Learn what she thinks about the future of growing food beyond our planet, including on Mars.

Jim Green: For humans to live, we need food. So how are we going to survive when we begin to live and work in faraway places in space?

Christina Johnson: It's really fun to see all these leafy greens that we've been growing in space for the last few years because the astronauts can eat them right away.

Jim Green: Hi, I'm Jim Green, and this Gravity Assist, NASA’s interplanetary talk show. We’re going to explore the inside workings of NASA and meet fascinating people who make space missions happen.

Jim Green: I'm here with Dr. Christina Johnson. And she is a NASA postdoc fellow at NASA's Kennedy Space Center in Florida. Christina works on a variety of projects related to growing plants in space. Welcome, Christina, to Gravity Assist.

Christina Johnson: Oh, thank you so much for having me here.



Christina Johnson works on plants in her laboratory at Kennedy Space Center. Credits: Raymond Wheeler/NASA

Jim Green: You know, when we think about growing plants in space, what are the kind of challenges that we have to consider? And how do we overcome them?

Christina Johnson: Oh, that's such a great question. So when we grow plants here on Earth, we have gravity, we have good airflow, we have the sunlight. And when we get into space, we lose a lot of that we, we can't access the sun because it's not safe to have that much sunlight in the space occupied by the crew. And so we need to bring in our own lights, we use LED lighting, because it's very lightweight, and we can bring just the right lights that we want, then we also have to think about airflow. In space, you get pockets of air, you get pockets with high co2 and low co2, and those plants need a more homogenous air source.

Christina Johnson: And so we use fans who bring fans in to move the air around the plants. Another thing that we run into is water. We love water, plants need water. And we need to deliver that water in a way that also delivers a little bit of air and oxygen to those roots. They'll suffocate without getting a little bit of air along with the water. And you don't really think about that. Because here on Earth, you have a lot of mixing in the water. And in space, you don't get that mixing so well, that’s really unique problems,

Jim Green: Yeah, boy, that sounds like a pretty tough challenge to me. So you know, when we take plants up? Or actually what do we do? Do we take the seeds up and grow the seeds? Or do we actually have starter plants? What's the best way to do that?

Christina Johnson: Oh, that's a great question. So there are a lot of different ways that we can do this, and a lot of different ways that have been done over the decades that we've been growing plants in space. But our favorite way right now is to send up seeds and grow things from seeds.

Jim Green: Wow. That's, that's phenomenal. Yeah. So So you know, so it's not like you got seeds floating around in the cabin, you got some sort of containment? What does that look like? And how do you how do you get the seeds to get going? Is it just from light and water? Or what kind of nutrients do they have to have?

Christina Johnson: So when we bring our seeds up there, they're stuck between two wicks, or they are stuck on seed films, which are a really great invention that we came up with here at Kennedy Space Center we have this, this film that the seeds are embedded in. And then we can take that film out, again, have it in a filing cabinet basically, and put that in in the hardware when we want to grow them. So that one was a great innovation, then we also have I've been playing around with pre-seeding mats, but we haven't sent those to space yet. Where I have the mats that I'm going to be growing my plants on. The seeds are glued down on that and very stable. And then we could plant them and add water.

Christina Johnson: So the key for getting germination going is adding water. And we can choose to add light at the same time or we can choose to add light a little bit later. And that's actually something I'm looking at to: At what point do we need to add that light to have really good growth? Do we need to add it right away? Different seeds actually have different requirements some plants really germinate the best when they're in the dark, and other plants germinate the best when they're in the light. And so determining which crops we're going to grow that's one of those little tests we have to do before we decide to grow them in space.

Jim Green: So what are the plants that we have really been successful and growing on the International Space Station?

Christina Johnson: One of those workhorse plants that can grow really well is mizuna, It's a mustard plant. And that one's been growing in pretty much every platform since we started growing plants in space. It grew on Mir, it grew on the shuttle, it grows on the space station. We've had many successful harvests with it and in many different kinds of plant hardware. That one's, that one's kind of our go to for, for testing to it's like okay, well this one work? Let's try it with mizuna. Mizuna does great, okay. Let's try it with something else. So mizuna one of those that just keeps coming up. And astronauts love to eat it too because it has this mustardy flavor. It's not a boring green.

Christina Johnson: Another one that does really, really well is outraged-gous red romaine lettuce, I just love the name of that one. We also have like a dragoon lettuce, that's also a red lettuce. And it's, it's kind of fun, because there's such a different color than what you'd expect out of a lettuce a lot of people think of green and they think of lettuce. And these are like a red, reddish, purplish green, kind of a bunch of different colors in the leaves. And they're really beautiful to look at. And, and they also taste really great too. They're more of a neutral flavor.

Christina Johnson: It's really fun to see all these leafy greens that we've been growing in space for the last few years because the astronauts can eat them right away. We call them “pick and eat” crops. We, we grow them, they can pick them and eat them right away. They don't have to do any preparation. Because you don't have the kitchen prep that you would have here on Earth in space. You know, we're looking not at replacing their diet, we're looking at supplementing their diet. So it's like okay, they can make lettuce wraps with this lettuce. They can do all these fun things with the food that they have.

Christina Johnson: Another thing that grew really, really well in space: That's peppers.

Jim Green: Peppers! All right.

Christina Johnson: So spicy hot peppers grew in the advanced plant habitat. And those did so well and the astronauts loved them and they took their tortillas and made tacos with them and things when it came time to eat them. So those, those were one that we were doing a lot of prep work for in advance of putting them up in space and LaShelle Spencer really screened a whole bunch of pepper plants and Matt Romeyn as well. They just, they just went through so many different kinds of peppers and they were like “okay, these do great with LED lighting.”

Christina Johnson: But the airflow, the direction of the airflow, wasn't quite what we needed. The flowers were pointing in a different direction than we expected, because of the lack of gravity. Basically, that's what it came down to.

Jim Green: Wow.

Christina Johnson: And the astronauts went in there and hand pollinated them. They took, you know, they took their little tools, and they came in, and they picked up some pollen from one flower and moved it over to the other so that the astronauts got to be the bees, right?

Jim Green: Wow.

Christina Johnson: So it was, it was really great. We ended up with a couple of great harvests and just recently came back to Earth for analysis.

Jim Green: When you think about plants here on Earth, you know, go through a day-night cycle, and therefore they have a certain length of time for which they can be harvested. How does that change on Space Station when you can actually have them under light the whole time? Or do you have to take them off and make it dark? Or well, how does that work?

Christina Johnson: That’s a great question. If we have too much light, we end up with photo bleaching. And we need to make sure we don't have constant light because those plants need a break.

Jim Green: Interesting.

Christina Johnson:  So we'll have photo periods. That’s the time when the light’s on compared with the time that lights are off. And so something like 16 hours on, eight hours off, in a given 24-hour period is pretty good. Sometimes we do 12 hours on, 12 hours off. It really depends on the crop, and what that crop really thrives with. But for a lot of crops, if we do 24/7 lights, it wears them down. Their chloroplasts break down, they end up bleaching out, and they aren't appetizing. (laughs)

Jim Green: Wow, that's fantastic. I mean, you know, they've evolved in [an] environment where there's a certain amount of time in light and dark, and taking them to space. You know, they need to rest just like humans do.

Christina Johnson:  Yeah, they do.

Jim Green: Who would have thought! Who would have thought? But doing that kind of research tells us also, that once we establish perhaps plants on Mars, which has about you know, the same kind of light and dark cycles we have on Earth. You know, one day on Mars is just a little more

Christina Johnson: A little bit longer.

Jim Green: …than 24 hours. Yeah, you know, they ought to do well.

Christina Johnson: For sure.

Jim Green: we don't have to change their clock or anything, right?

Christina Johnson: Yeah, their circadian rhythm is going to adjust pretty well. We have plenty of plants here on Earth that that do well in environments, where if you think about, in Alaska, there's months where you have sunshine and months where you have darkness. And there are plenty of plants that can just go dormant, and then come back.

Christina Johnson: So we might have variation like that on Mars where we have like, “Okay, in this area, you get more sun this time of the year and this area, you get less than this time of the year,” and depending on where we're growing on Mars, we might have different needs.

Jim Green: That's right, there are seasons on Mars, too.

Christina Johnson: Yeah. (laughs)

Jim Green: Well, you know, every astronaut I talked to that comes back from the International Space Station really loves to go into the module with the plants. And you know, I've been calling that the “green effect,” no pun intended.

Christina Johnson: (laughs) Love it. (laughs)

Jim Green: Because, you know, they get to see the beautiful greenery of the plant. But I think there's more to it. Why do you think this is happening? What really piques their interest in these plants?

Christina Johnson: Well, there's the connection to the Earth. A lot of astronauts are from agricultural roots. And they've grown up with gardens and they've grown up with plants and they don't realize until it's gone just how much they missed that.

Christina Johnson: Another thing we notice: One of our horticulturists [Jess Bunchek] just recently came back from Antarctica. She overwintered in Antarctica and was taking care of a greenhouse the entire time there and supplementing her crew’s diet with that. There were 10 people who overwintered in Antarctica. And this is called the Eden ISS project and it's a collaboration with the DLR, which is the German Aerospace Agency. She took care of these plants. It was a separate module from the rest of what they were living in. So, she had to walk in white-out conditions following a rope to this greenhouse where she would walk in, she would get rid of all of her winter clothes, and she would be in this amazing green, lush environment. And she would take care of the plants, and then she would trudge back with a cooler full of delicious produce to share with the rest of her crew, right?

Christina Johnson: And just the fact that she was so isolated and so... [in] such a boring environment all around them. I mean, Antarctica is beautiful, some days, but other days, you just can't see anything. It's just white. And she was able to come back and have that fresh fruit to share with people and the crew was like, “Oh, can I go help you in there today?” (laughs)

Jim Green: Well, I think also it's the smells!

Christina Johnson: Yes, the smells. Oh, another thing. When the world kind of shut down in March of 2020, we had a lot of students interested in growing plants. Jacob Torres, who's one of the horticulturists here at Kennedy Space Center, he started the Space Chile Grow a Pepper Plant challenge. And he sent seeds to teachers and students, and [it] ended up being a big community outreach effort where they would grow pepper plants in their house, in whatever lighting they had, and I participated in this, I had a little aerogarden that I decided to grow pots of pepper plants in. And I had that, that light, and we had them in our living room for a good, hmmm, six months. And it smelled like peppers in our living room as they were fruiting and flowering. And it was just so fun.

Christina Johnson: But eventually, it got to the point where it was like, “Okay, peppers all the time! Oh, my goodness! When are we going to call this done? (laughs)

Jim Green: (laughs)

Christina Johnson: When are we going to grow something different?” Because we would planted other things and have other things growing like beans, but the peppers would just take over. And that's another thing to consider when growing things. The peppers were growing in the Advanced Plant Habitat at the International Space Station, which is enclosed. If they were growing in Veggie it would be a very different experience for the crew. Something we found in our house -- which maybe doesn't relate to spaceflight, I don't know -- but with our six pepper plants we had days when there were lots of fruit on those plants. And we'd walk up to that corner of the room and our eyes would start watering and it was just spicy tasting the air.

Jim Green: (laughs)

Christina Johnson: (laughs) I didn’t expect that!

Jim Green: Well, this brings up of course, the question about, you know, what do you think are the type of plants we should be growing on the Moon and then on Mars?

Christina Johnson: I think that on the Moon, it's a great opportunity for us to test things for Mars later. But it's also a great opportunity to test things for the Moon. (laughs) Because I do think that we'll have a sustained human presence on the Moon in the near future.

Christina Johnson: I think that we're going to need supplemental food, because when we're on the Moon, we can get regular food delivery from Earth. It's expensive. It's hard. But it's not impossible. When we're talking about Mars, it's really hard to get resupply out there. We're talking years, and by the time the food gets there, it might not be the best quality. Vitamins degrade over time, we're going to be lacking in vitamin C. That's one that falls apart within it a year and a half. We're going to be lacking in Vitamin K, [it’s] one of my favorites because people don't really know about vitamin K that one's found in leafy greens and it's absolutely essential for human life. Yeah, so when we're talking about the Moon, we're talking about things to supplement the existing food system. When we're talking about Mars, we're talking about more staple crops. Maybe we're talking about the rice and the potatoes and the sweet potatoes. Sweet potatoes are one of my favorites, because you can eat the leaves, too – the young leaves, which are really tasty.
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Odp: [NASA Gravity Assist] : Season 5
« Odpowiedź #52 dnia: Sierpień 27, 2023, 11:25 »
Gravity Assist: What Will We Eat on Mars? (2)
May 20, 2022


Christina Johnson is a postdoctoral fellow at NASA's Kennedy Space Center in Florida. She works on plant experiments for the International Space Station. Credits: Christina Johnson

Jim Green: Well, what are some of those questions that we need to answer in terms of getting the astronauts to grow their own food, say on Mars?

Christina Johnson: So when we're having our astronauts grow their own food, do we want to have them doing the manual labor? Or do we want to have it automated? How much automation is desirable? And this is actually a trade-off that we see now, with vertical farms and indoor agriculture here on Earth. There's some companies that have made the conscious choice to have no automation whatsoever, and just rely on their own crew to handle all of the seeding and all of the harvesting, and all of that, because they found that when they added automation, it added the need for additional engineering staff, and they realized they could actually run a leaner business with their people doing everything.

Christina Johnson: But then there's others [businesses] that grow really big, and the automation is everything, and it's an economy of scale. So are we feeding astronauts and having this food that we make in space be their sole source of nutrition? When we get to that, we're going to need that scale. We're going to need some automation or a lot of automation. When we're looking at supplementing, maybe we don't need that automation quite as much. Maybe we could automate seeding and maybe automate harvesting, but the daily care of those plants, the astronauts would still do.

Christina Johnson: Another thing that we want to think about is: How do we help those astronauts? Are we going to choose astronauts who are agronomists and botanists and horticulturists? Or are we going to choose engineers? If we need those astronauts to be dependent on the agronomists here on Earth, the ground crews, then we need to make sure that communication is going to be adequate, and fast enough and good enough. And maybe we'll want some multispectral or hyperspectral imaging on those plants, like we have on the fields here on Earth. The USDA and NASA worked together to get the satellite imagery for the fields. Maybe we need that on the crops that are in space.

Christina Johnson: And we can we can talk back and forth and say, you know, “these plants are diseased, please cull them now, so that it doesn’t spread.” And maybe we'll want to say, “Oh, these are dehydrated, there might be a fault in the water delivery system? Please check for that.” Who do we send and do we send both? Do we send the engineers and the plant scientists?

Jim Green: In the last episode, we talked to Dr. Anna-Lisa Paul of the University of Florida where she and her team were able to grow plants called Arabidopsis thaliana in samples of lunar regolith brought back by the Apollo astronauts. Really cool. Christina, you also used this same species in your Ph.D. research, right?

Christina Johnson: So for my PhD, I got out to Miami University, which is a small school in Ohio. And I thought I was just going to be in a lab where other people did a bunch of spaceflight research. And I got to look at the plants that came back. But turns out while I was there, my first semester, I started writing a grant proposal for spaceflight. And turns out, that proposal ended up being useful because there was a call that came out suddenly, for a series of experiments on the Shuttle. They were looking for three investigative teams to run some experiments in the BRIC hardware, which is a closed system with Petri plates that you can grow plants in.

Christina Johnson: And our proposal got picked up, I was very excited about that. And so I got to see from start to finish what it was like to do a spaceflight study. I got to come out to Kennedy Space Center and put my plants, get them into the hardware, get them loaded up in the hardware, say goodbye to them, as they loaded them up onto the shuttle, I got to watch the shuttle launch, I got to watch them come back. Oh, my goodness, a Shuttle landing is such an experience. And then once they came back, within a couple hours, those samples were back in our hands, and I got to take them back to the lab and start looking at them right away. And I was so excited for that experience. I looked at how they grew physically, their morphology, the physical characteristics, and that's where I noticed, the roots were tilting. That was very interesting. And then we also had the opportunity to do some transcriptomics on those plants as well. And so I got to see what genes were upregulated and downregulated in spaceflight, and the differences there. And then I was able to compare my results with the other three investigative teams that also grew very similar plants at the same time under those same conditions. So that was really a great experience from my PhD.

Jim Green: Well, I can talk to you forever about some of the research that you're doing and what we also need to do to get ready to live and work on a planetary surface. But unfortunately, we must come to a close. So I always ask my guests to tell me the person, place, or event that gave them so much energy, so much excitement, that they became the scientists they are today. And I call that event a “gravity assist.” So Christina, what was your “gravity assist?”

Christina Johnson: Okay, so I thought a lot about this. And I'm gonna talk about two things. So first, when I was a child, I really liked Star Trek: The Next Generation. It just came out when I was young. And I was very much into the world of make believe. And so I really clung to this one character, Keiko O'Brien, she's the head of the Conservatory on the Enterprise. And later, she was on Deep Space Nine too. But I thought she was only in a few episodes here and there. But the would interact with Beverly Crusher, the doctor, and she would bring in plants and, and they would have this great exchange of information like, “Oh, this plant would be good for human health.

Christina Johnson: And so in my mind, I built this whole fantasy around O'Brien and I would go on xeno-ethnobotanical expeditions to go collect the best medicines from the most far reaches of the universe, and I would bring them back to my sister who was pretending to be Beverly Crusher. And I would, you know, I would be like, “Oh, look, I can save your patient because I found this!” And she would be like, “Oh, great, yes, let's use that.” And Keiko O'Brien was definitely my inspiration for thinking about space and plants. But then that was all fantasy. I had no idea that this was a real area of research, until I was an undergraduate at UC Berkeley working in the lab of Dr. Chelsea Specht.

Christina Johnson: And she mentioned I was working on ginger floral development, you know, beautiful things. very applicable to Earth. Ginger is great. I think we should definitely have it on Mars.

Jim Green: (laughs) Okay.

Christina Johnson: She was like, “Christina, you love space!” I'm like, “Yes, I do. I really love space.” She's like and you love plants. “Did you know you can bring those two together?” And I was like, “Wait, what?” She was like, “I think for your PhD, you should really work with space and plants. And here's a few researchers who do this.” And so I wrote a blog entry about John Kiss, who does space research, he had plants growing on the European Modular Cultivation System. I just wrote a blog entry about him and his research. He found that blog entry and reached out to me and said, “Come visit our lab. Let's see if it's a good fit for graduate school.”

Jim Green: Wow! And I was hooked.

I was like, “You've got to be kidding me. I can do space and plants at the same time?”

Jim Green: Your dream came true.

Christina Johnson: Yes. So my gravity assist was Keiko O'Brien fiction. And then reality was Chelsea Specht to who told me “Hey, this is a thing.” And then John Kiss who was like, “Yes, let's get you. Let's get you into this area of research.”

Jim Green: Fantastic. Christina, thanks so much for joining me for a fascinating look at how we are planning and do grow plants in space well beyond Earth.

Christina Johnson: Thank you so much.

Jim Green: Join me next time as we continue our journey to look under the hood at NASA and see how we do what we do. I'm Jim Green, and this is your gravity assist.


Credits
Lead producer: Elizabeth Landau
Audio engineer: Manny Cooper
Last Updated: Jun 22, 2022
Editor: Gary Daines

Source: https://www.nasa.gov/mediacast/gravity-assist-what-will-we-eat-on-mars
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Odp: [NASA Gravity Assist] : Season 5
« Odpowiedź #53 dnia: Wrzesień 03, 2023, 10:21 »
Co słychać na Marsie?
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Nina Lanza: And really excitingly we also added a microphone, which seems a little bit crazy, but it's not. There's a great science reason for it. We want it to listen to the sound of the LIBS laser as it vaporized material because it actually makes like a shockwave as that plasma expands. And you can learn a lot about a rock by listening to that.

Gravity Assist: This is What Mars Sounds Like, with Nina Lanza (1)
Jun 17, 2022


Nina Lanza, the principal investigator for the Curiosity rover’s ChemCam instrument, holds a model of Mars in Abiquiu, New Mexico. Credits: Minesh Bacrania

With two microphones aboard the Perseverance rover, we can listen to Mars from its surface like never before. In addition to hearing how wind sounds on Mars, we can also listen to Perseverance driving on the surface, the Ingenuity helicopter flying nearby, and more. Nina Lanza of Los Alamos National Laboratory plays some of these sounds and explains why these awe-inspiring sounds also have scientific and engineering value.

Jim Green: What does Mars sound like?

Nina Lanza: We've had these beautiful panoramic images of Mars for a long time. But now to add that sound, it really just makes me feel that much closer to standing on the surface.

Jim Green: Hi, I'm Jim Green, and this Gravity Assist, NASA’s interplanetary talk show. We’re going to explore the inside workings of NASA and meet fascinating people who make space missions happen.

Jim Green: I'm here with Dr. Nina Lanza. And she is the team lead for space and planetary exploration in space and remote sensing organization at the Los Alamos laboratory in New Mexico. She is the principal investigator for the ChemCam instrument aboard the Curiosity rover, and a science team member for the SuperCam instrument on the Perseverance rover. Welcome, Nina, to Gravity Assist.

Nina Lanza: Thanks, Jim. I'm excited to be here.

Jim Green: Well, first, what I want to do is hear a little bit about these fantastic instruments you work on.

Jim Green: Curiosity’s got 10 instruments. And when I started at NASA Headquarters, it was moving to a key decision point. And we selected this beautiful instrument called ChemCam. Tell us about the ChemCam instrument.

Nina Lanza: Well, sure. Yeah. So, you know, when ChemCam was actually selected, I’m the second PI, I was only a graduate student. And I actually started working on the project essentially right after the selection. So I was able to see this project through this entire time, which has been an incredible learning experience for me.

Nina Lanza: So its name is short for “chemistry and camera.” So as you might imagine, we do both chemistry measurements and we take pictures. So our main chemistry technique is called laser induced breakdown spectroscopy, or LIBS, L-I-B-S. And the way this works simply is that you can focus a laser at a target at a distance from the rover of up to 7 meters, so about 23 feet. So you don't have to touch a sample. And you vaporize just the little materials. So you're actually heating that up so hot that it turns into a vapor, and that plasma emits light, and you can look at the color of that light back on the rover. And that will tell you what elements are in that rock.

Jim Green: Yeah, it's really fantastic, the concept of taking a laser and beaming it on a rock and vaporizing it.

Jim Green: Well, what's been some of your favorite results from ChemCam?

Nina Lanza: There are so many good results. And it's been 10 years, so there's so many good ones, you know. I mean, I think the biggest one was really our first result, where we figured out that the soils on Mars are hydrated. They have water in them. And that's an amazing result. People always ask, “Well, where did all that water on Mars go?” And I tell them, “It's still there. It's there right now, it's just not in a form that we tend to recognize.”

Nina Lanza: There are previous missions that, you know, using remote sensing, orbiting spacecraft instruments, you know, we could tell that there were hydrated signatures. And some of those signatures made sense with the context, but others just really didn't. Or like, what's hydrated there? And the answer is: the dust, and the dust is everywhere. Dust is ubiquitous on the surface of Mars. So that was a really incredible results that really answered some outstanding questions we had about Mars for a long time.

Nina Lanza: You know, we've just learned so much about Mars in these 10 years. I think ChemCam has about 900,000 individual spectra. So that’s 900,000 laser shots. I mean, that's a crazy amount of data. And I'm sure there are many PhD theses waiting to be written, right? We have barely scratched the surface of what those data can tell us.

Jim Green: Yeah, that's fantastic. And I know Curiosity is still very healthy and going strong. Well, I want to switch gears a little bit and talk about another spectacular rover on the surface of Mars. And that's Perseverance.

Jim Green: You know, the landing site of Curiosity is this big crater, Gale Crater, and another crater Jezero Crater, is where Perseverance is. Are they close? Or are they far apart?

Nina Lanza: Well, they're not that close, you know, on Mars. And people always think they look close, because they look at a map, but that's thousands of kilometers away. So we're just going to wave our robotic arms at each other, we'll never go and visit. But these craters are actually very similar in a lot of ways because they both represent similar aged craters that were probably filled with liquid water. They represent this time on Mars’s history where water appears to have been abundant. And so we have these lakes. So they give us these two different views of what lakes on Mars were like.

Jim Green: The way I think about it, too, in terms of how far apart they are, is: when the Sun is going down with Curiosity, it's overhead at Perseverance.

Nina Lanza: That's a great way to look at it. You know, I actually hadn't thought about the time zone change, you know. But of course, they are in different time zones. I love that.

Jim Green: You know, I was head of the [NASA] Planetary Science Division when we landed Curiosity. And then we immediately started to get the approval process together for the next big rover. And that ended up being Perseverance. Well, we finally created a package of seven fabulous instruments, several from other countries. And one of these instruments is the SuperCam instrument. So can you tell us a little bit about SuperCam?

Nina Lanza: Of course, yes, so SuperCam is really the sister instrument of ChemCam. And thank you for bringing up that, you know, this is really an international effort. So ChemCam is actually a joint project between the US and France. And so now, SuperCam continues that really strong collaboration with France. And we've actually added some Spanish collaborators as well. So I think it's really important to note, you know, we don't do these things necessarily alone. This is really a team effort.

Nina Lanza: SuperCam has a lot of the same instrumentation techniques as ChemCam, but has a few extra tricks up her sleeve. So we continue to do the chemistry with the LIBS, laser-induced breakdown spectroscopy. We still zap rocks. But we've also added another laser technique called Raman spectroscopy.

Nina Lanza: Now, this laser doesn't actually vaporize material; it scatters light off of molecular bonds. So you can actually figure out, with the same instrument, both chemistry -- so what are the elements -- and mineralogy -- how are those elements arranged. And with those two pieces of information, you can actually uniquely identify geologic materials. So it's really a very powerful combination of techniques.

Nina Lanza: And really excitingly we also added a microphone, which seems a little bit crazy, but it's not. There's a great science reason for it. We want it to listen to the sound of the LIBS laser as it vaporized material because it actually makes like a shockwave as that plasma expands. And you can learn a lot about a rock by listening to that.

Jim Green: Well, I tell you, the concept of having a microphone on Mars has been something I have wanted to do for many years. And I am so delighted we ended up with two on Perseverance. And indeed it really turned out to be science-driven, engineering-driven.

Jim Green: What really happened that really helped that argument of getting a microphone on Perseverance really started with Curiosity. As Curiosity was driving along, and it was going through a very rough area, and the rocks were so sharp, it was punching holes in the wheels, and we didn't realize that. And of course, if you don't have any wheels, you're not going to go anywhere. And so the concept is, how are we going to determine this?

Jim Green: We needed additional sensor capability. And having some sort of microphone where we can hear the creeks and the cracks and, and try to understand what's happening to the rover as a function of time was really going to be an important addition to it. And now Perseverance with these two microphones, [we] have the opportunity to really hear what's going on on Mars. So how do these microphones work?

Nina Lanza: So both of these microphones and I know what it's one is the entry, descent and landing, or EDL microphone, which is bolted to, I think, the lower left. and the SuperCam microphone, which is bolted to, essentially attached to the mast unit, which is, you know, the head of the rover. So they're separate instruments. Both of them are really pretty straightforward. They’re pretty simple instruments, right, they're not, they're nothing fancy. They're both really commercial off-the-shelf parts, which people are really shocked by, but microphones inherently are very simple instruments. They just essentially need to sense pressure. So they just need this membrane that will vibrate and turn that into an electrical signal.

Nina Lanza: They're very simple, but they can actually tell you so much just about the environment. We can use them to do, you know, both science and engineering, right? So one of the things that SuperCam has been doing is, many times when we when the MOXIE instrument turns on -- this is the in-situ oxygen generating experiment -- you know, we'll turn on our microphone to listen to the sound of their compressor, because actually listening to the compressor gives you a very good sense of how well it's functioning.

Nina Lanza: So we can actually help them understand the state of their instrument’s health, just by listening to it, you know. And, of course, I think the EDL microphone has recorded the sounds of the, the wheels of Perseverance driving, which is a very unusual sound, but it also tells you that you can, you can hear that things are okay with those wheels, you don't have to just rely on looking at them. You know, but then, of course, we can listen to the sounds around us of Mars, which is an amazing dimension to add. You know, we've had these beautiful panoramic images of Mars for a long time. But now to add that sound, it really just makes me feel like that much closer to standing on the surface.

Jim Green: Yeah, I know what you mean. I really wanted to have the microphones on all the time, bringing that data back, pumping it into my office.

Nina Lanza: (laughs)

Jim Green: So as I'm sitting there working, I can hear the sounds on Mars, that would be fantastic. And in fact, of course, at night on Mars, I wanted to hear the crickets.

Nina Lanza: (laughs)

Jim Green: Okay, so…(laugh) the pressure on Mars, you know, the atmosphere is so much different than here on Earth. It's about a percent of our atmospheric pressure. And the composition is so much different because it's dominated by carbon dioxide. So we expect these sounds to sound different than they would here on Earth. Were there any kind of surprises when you started to hear the sounds because of that?

Nina Lanza: Yes! When we thought about what would we expect to hear on Mars, we understand very well, the differences in the atmosphere between Earth and Mars. So we have some sense of how those sounds would be different. But of course, you know, models are great, and they really help us, but they are not observations. And so we really had to take observations to say, okay, are our models correct? And the answer was: no. (laughs) They were not correct. It turns out that sound actually propagates a lot more readily in the Martian atmosphere than our models suggested.

Nina Lanza: Before we even sent these microphones, some naysayers said, “Oh, you'll never hear anything, you'll never hear anything, there's just no way sound can propagate.” And it turns out sound is propagating extremely well. So things are louder than we would have thought. Now, that being said, they’re quite quiet, you know, there's not a lot of air molecules on Mars.

Nina Lanza: So its sounds are attenuated. But we can hear sounds much further away than we had predicted. And so it's really meaning that these observations are allowing us to understand the Martian atmosphere and a whole new way that models never could have let us see.

Jim Green: Well, I know you've got a bunch of sound files, and I'm dying to hear them. So pick one and let's listen to it and then talk about what we're hearing.

Nina Lanza: Well, sure, let's see. Maybe since we were just talking about sound propagation, let's maybe listen to the sound of the helicopter, Ingenuity.

Jim Green: Okay, okay.

Listen to the sound of the Ingenuity helicopter

Jim Green: Well, that's fantastic. And I mean, you know, when you think about it, Ingenuity is not really very close to the rover.

Nina Lanza: No!

Jim Green: We don't want Ingenuity crashing into Perseverance. So it's at least, you know, 50 meters away. So the ability to hear anything about what the helicopter is doing is really exciting. And as you said, it really gives us a great idea of how that sound is propagating even over long distances.

Nina Lanza: Exactly, you know, so our models predicted we would not be able to hear that sound more than 60 meters away. We heard it over 100 meters away, which is amazing. And what Ingenuity allows us to do is have a standard sound that we can, you know, put at a known distance from the rover. It's like the perfect acoustic experiment.

Nina Lanza: You know, and of course, it wasn't designed as that. But it really allowed us to do this project where we say, look, let's get this sound. We understand exactly the, signal of those rotors, so we know where, and we know where it is, so that we can actually put that together to make and improve our models of attenuation in the Martian atmosphere. And it has worked beautifully. And again, we were shocked. We could hear this. In some ways, it's [a] very mundane sound. We've all heard the sound of rotors, but that's the first rotorcraft on another planet, which is amazing!

Jim Green: Yes, it really is amazing. I tell you. So you know, when we know a lot about the climate on Mars. We have a weather station from Spain, on both Perseverance and on Curiosity. And so we can measure the wind velocity, and the pressure and a number of things like that. And so, indeed, can we hear the wind on Mars?

Nina Lanza: We can. And you know, in many ways, it sounds like the wind on Earth, but in other ways it doesn't. So maybe we can take a listen.

Jim Green: Yeah, let's do that.

Listen to the sound of wind on Mars

Jim Green: You know, that's kind of like a windy day. Is it like that all the time that you turn it on? Is that kind of the background? Or can it be really quiet with no wind at times?

Nina Lanza: It's incredibly variable. So it really depends on a lot of factors, you know, the season, the time of day, and just, you know, random perturbations in the atmosphere, right? So there are times of day on Mars that are louder and quieter. So that is probably a mid-day sound, right, where we have the most turbulence. So we hear that wind, which is a kind of a low frequency sound very similar to what we would hear on Earth. Now the difference, of course, is that you know, even though that wind, it sounds very similar, it doesn't have the same force behind it because the atmosphere is so, so much less dense than Earth.

Nina Lanza: So you know, you hear it sounds like it's a really strong wind, and it is for Mars. But if you were to stand out there and feel it, you probably would barely feel it on your skin. Of course, I don't recommend standing on Mars without a spacesuit. So you shouldn't do that experiment, but it's a gentler winter than it sounds.
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Gravity Assist: This is What Mars Sounds Like, with Nina Lanza (2)


Nina Lanza, a planetary scientist at Los Alamos National Laboratory, on Axel Heiberg Island, Nunavut (Canadian Arctic) in May 2022. Credits: Leila Battinson

Jim Green: That's incredibly fascinating. Well, what other sounds do you have on Mars? Can we hear the rover drive?

Nina Lanza: We can, and we've actually recorded that. And it's a very weird sound as you'll hear, because the rover doesn't have nice squishy tires. It actually has metal wheels. And so you can actually hear that sound of that metal on the rocks in the soil and it's kind of a little unnerving, I think. It sounds like something's wrong, but of course, nothing is wrong. Everything's fine. So maybe we'll take a listen.

Listen to the sound of Perseverance driving

Jim Green: Yeah, it sounds like it's creeping, crawling along. And then you know, stopping for a second or two and then creeping some more, and when you think about it, you know, Perseverance has got a heritage of intelligent software that's really started with Spirit and Opportunity and then developed into what Curiosity is using and that means, we tell it where it wants you to be at a certain location, and you figure out how to get there. And so it's got to take pictures, it's got to do some analysis in and in having it creeped along.

Nina Lanza: It's amazing, right? The rover can just decide, hey, you know, I don't want to drive straight from point A to B, I need to make a little turn here for my own safety, which is remarkable, right? It's amazing that that we have built a machine that can make those kinds of decisions.

Jim Green: Yeah, I hope from now on every time we go to Mars, we take a microphone. I'm really hoping that that will be a main part of our infrastructure. I think it's just so essential. Now, are there any other scientific insights that we're learning from the sound recordings?

Nina Lanza: Oh yes, well, maybe I can play you one more sound, my favorite sound,

Jim Green: Okay!

Nina Lanza: …which is of course the SuperCam lasers zapping that's the one that I listened to the most, because that's what I'm using to study rocks. So what this sound is, essentially, is that when you shoot the laser at a rock, it's at a distance from the rover. So then you make this plasma, the shockwave that makes a snapping sound, that snapping sound, then vibrates through the air and travels back to the microphone on the mast. And so you can actually hear this at a distance. It's a very small thing, but we can hear it very clearly. So maybe we'll take a listen.

Listen to the sound of the SuperCam laser

Jim Green: Now, what we heard, you know, are the individual beams. But it was for only one hole, right? We didn't go to the next hole? So we're really burning that one hole in the rock.

Nina Lanza: Exactly right. So this is just, you could hear its 3 hertz cycle. So it's not that fast. And each time you hear that snap, you vaporize just a little more material in the same hole. We're drilling down into the surface of a rock, but you know, only a few microns, but that's what you're hearing.

Jim Green: Wow, that's fantastic.

Jim Green: What's next up for both Curiosity and Perseverance and their instruments?

Nina Lanza: Oh my goodness, so much. It's such a great time to be a Mars scientist! You know, there are so many things going on. So for Curiosity, of course, we're continuing our ascent of Mount Sharp, and we're continuing to explore unexplored terrains. And so we're going to go through this transitional period to understand you know, how do the lakes end up drying up in in Gale Crater? And so, you know, I'm really looking forward just to continuing to see, you know, this progression. In Jezero crater, you know, I am so excited about sample return.

Nina Lanza: So one of the things that Perseverance is doing, it's actually not only a standalone science mission, it's also collecting samples to return to Earth in a future sample return mission. And so one of the most exciting things that we do is to select samples to return to Earth. And these are going to be samples that are going to be in our laboratories within the next 10 years. It's so exciting, it's going to change everything. So for me, that's one of the most exciting aspects of Perseverance. And of course, we're on right now, in this beautiful delta, which is a deposit made by flowing water.

Nina Lanza: And so all of us on the team, like, really want a piece of that delta. That's like the most exciting sample I can think of, you know, from Mars. So, you know, we're going to be able to take those samples. And of course, we're going to have to be patient and wait for them to come back. But we know they're coming back.

Jim Green: Well, Nina, I always like to ask my guests to tell me that person, place or event, or thing that happened to him that got them so excited about getting in the sciences and being the scientists they are today. And I call that event a gravity assist. So Nina, what was your gravity assist?

Nina Lanza: Well, when I was seven years old, my parents took me to an open observing night at a local university to see Halley's Comet. And so this was, you know, this a comet, a short period comet that comes back every about 76 years. So it was a really a big event. I didn't know anything about space. So there was a lecture before the observing. And I admit that I don't remember anything about that. But when we went out onto the roof, and I looked through that telescope, I was shocked to see something that looked so, just, real, something that I had never seen before.

Nina Lanza: And I realized at that moment, that the sky was not a dome. The sky is three-dimensional space and who knows what's out there! And for me, that was just a pivotal moment. I realized there was nothing more interesting or exciting to me than figuring out what was out there. And so I have really pursued that for the rest of my life. I had no idea, of course, when I was seven, how to do that or what that really meant, but that that sparked this lifelong fascination with space that I carry with me today.

Jim Green: That's great. Well, Nina, thanks so much for telling me about the science and the sounds of Mars.

Nina Lanza: Thank you so much for having me. I love chatting about this stuff. And thank you so much for, for helping us get there!

Jim Green: My pleasure.

Jim Green: Well join me next time as we continue our journey to look under the hood at NASA to see how we do what we do. I'm Jim Green, and this is your Gravity Assist.


Credits
Lead producer: Elizabeth Landau
Audio engineer: Manny Cooper
Last Updated: Jun 17, 2022
Editor: Gary Daines

Source: https://www.nasa.gov/mediacast/gravity-assist-this-is-what-mars-sounds-like-with-nina-lanza
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« Odpowiedź #55 dnia: Wrzesień 10, 2023, 07:45 »
O nadziejach związanych m.in. z poszerzeniem wiedzy nt. Urana dzięki obserwacjom JWST.
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Naomi Rowe-Gurney: Just like on Earth, we have like things like the mantle happening inside. It's like the remnant of the, the creation of the planet is still hot on the inside and it's only very slowly cooling down. And that's what we expect to see with all of the other planets as well — a hot interior leftover from creation. And that's not what we see at Uranus. We see a negligible internal heat. So it looks like there's no internal heat really going on at all inside. And that's very strange. And one explanation is that Uranus was hit by something really big, and kind of turned inside out. And all of that internal heat got lost.
https://www.esa.int/Science_Exploration/Space_Science/Webb/Webb_scores_another_ringed_world_with_new_image_of_Uranus

Gravity Assist: It’s Raining Diamonds on These Planets (1)
Jul 1, 2022


Left: Arriving at Uranus in 1986, Voyager 2 observed a bluish orb with subtle features. A haze layer hid most of the planet's cloud features from view. Right: This image of Neptune was produced from data from Voyager 2’s flyby of Neptune in 1989, and shows the Great Dark Spot and its companion bright smudge. Credits: Left: NASA/JPL-Caltech ; Right: NASA

Uranus and Neptune are two of the many exciting and mysterious objects in our universe that the James Webb Space Telescope will soon begin to explore. Temperature and pressure conditions are so extreme on these planets that carbon atoms could be crushed into diamonds in their atmospheres. And did you know that Uranus orbits on its side? Learn more about these planets and the Webb telescope’s upcoming observations from astrophysicist Naomi Rowe-Gurney, our guest on this week’s Gravity Assist.

Jim Green: We have two ice giant planets in our solar system, Uranus and Neptune. What will we find out about them when the James Webb Space Telescope takes a look?

Naomi Rowe Gurney: That will give us a massive insight into these other solar systems that we're seeing.

Naomi Rowe Gurney: I had so many teachers and tutors, and just people in my life that said:

Naomi Rowe Gurney: Maybe science is a little bit hard. Like, try doing something else. And I'm really glad that I didn't listen to them and I let my heart decide.

Jim Green: Hi, I'm Jim Green, and this Gravity Assist, NASA’s interplanetary talk show. We’re going to explore the inside workings of NASA and meet fascinating people who make space missions happen.

Jim Green: I'm here with Naomi Rowe-Gurney. And she is a postdoctoral research associate at NASA's Goddard Space Flight Center, through the Howard University in Washington, DC. Now, she specializes in the study of two of my favorite planets, Uranus, and Neptune. And she'll be using the Webb Telescope to find out more about these fabulous ice giants of our solar system. So welcome, Naomi, to Gravity Assist.

Naomi Rowe-Gurney: Thank you so much for having me. I'm really excited to be here.

Jim Green: Well, I've got to tell you, you know, we just haven't been back to the ice giants in so long after Voyager 2 flew by both of them [in the 1980s]. Not Voyager 1, Voyager 1 went on its way. But only Voyager 2 has observed, you know, those two beautiful ice giants. And you've been studying those for a long time. What is your favorite aspects of these ice giants? And why do we call them that? Why aren't they just gas giants?

Naomi Rowe-Gurney: Yeah, so I love the ice giants. I think I love them mostly because they haven't been looked at very much. I initially wanted to do my PhD on these two planets because there were so many unanswered questions. And we just really don't know even like the fundamentals of where they came from, and why they are the way they are, and why they're called ice giants. I mean, people are still kind of debating that name and whether it's appropriate and whether they should really be called rock giants, because who knows what's inside?

Naomi Rowe-Gurney: It really takes a mission, a proper mission with like an orbiter to look at the gravity of a planet to be able to figure out what's happening on the inside.

Jim Green: Now the composition of the atmosphere has kind of given us that clue that they're different than Jupiter and Saturn. And that's because it's got a variety of ices.

Naomi Rowe-Gurney: Mhm.

Jim Green: And you've been working on the thermal structure and composition, what is the most exciting things that you've been finding out?

Naomi Rowe-Gurney: Yeah, so that's the reason why they're blue, because they have high levels of methane in their atmosphere. I study the middle atmosphere, which is like the stratosphere and the upper troposphere. And that's kind of down to around one bar, which is around the same pressure that we have here on Earth, on air. So that's kind of the level that I look at.

Naomi Rowe-Gurney: And what we see there is that the Sun interacts with the methane in the atmosphere, and it breaks down the methane into lots of different hydrocarbons. So lots of these chains of different things with hydrogen and carbon in [them], with lots of fancy names like diacetylene and acetylene and methylacetylene, all of these. And we still don't really know everything, like the composition of everything that's in there, and we're still finding new things all the time. And that's why the JWST is so exciting, because we are going to be able to see a lot more of what's going on, and a lot more of these like complex hydrocarbons and things.

Jim Green: A couple of news releases that I've seen have concepts where carbon gets hardened, almost to the point, or maybe to the point of being diamonds. Do we see those kinds of things and Uranus and Neptune's atmospheres?

Naomi Rowe-Gurney: So I mentioned methane being the reason why these two planets are blue. Well, methane has carbon in it and that carbon can occur by itself and also be crushed by the immense pressures that happen, like, deep in the atmosphere, so much deeper than the levels that I look at. And inside the planet, when it gets really hot and really dense, these, these diamonds form and accumulate, and then they become even heavier. And that means that they kind of rain down in the atmosphere. But it's not the rain that we see here because these pressures are extreme, and you'll never be able to get there as a human. So even if these diamonds do exist, we would never be able to go and grab them. So… unfortunately.

Jim Green: Yeah, unfortunately. Okay. (laughs)

Jim Green: Well, you know, one of the really exciting things about planetary science is that when we go from planet to planet, we look at some things that are similar, in addition to the differences. And one thing we look for is lightning. Now here on Earth, we see our lightning but in the upper atmosphere there's some really spectacular forms like “sprites,” we call them and “elves” and blue “jets” and all kinds of exotic discharges that happen in our own atmosphere. Do you think we'll find those at Uranus and Neptune?

Naomi Rowe-Gurney: Yeah, definitely. I think that there's already been some research done on the kind of traces that we find in, in chemicals that is left behind by lightning and things. That research has already been done using some ground-based telescopes. So that is exciting stuff that's already happening on Uranus and Neptune that we're seeing. The lightning on other planets is similar, I think, to the lightning that we have on Earth as well. So all of those, like elves and sprites and things are also things that we're trying to look for, on, on other planets like Jupiter, Saturn, Uranus, and Neptune.

Jim Green: Well, you know, I think the Voyagers using the plasma wave experiment, did indeed find lightning, at least at Neptune, and at Uranus. That's really exciting. So, so that changes chemistry, too, in the atmosphere.

Jim Green: One of the one of the really great things that that have happened, is we've been monitoring Uranus and Neptune with Hubble, you know. So we have many years of Uranus and Neptune data. Hubble observed some big spots on Neptune recently. What's that all about?

Naomi Rowe-Gurney: Yeah, so Hubble looks at the near-infrared and the visible wavelengths and in visible we can look at what's happening in every color that we can see with our eyes. So these spots on Uranus and Neptune appear as like these blue dark spots, just like the “great dark spot” that we saw with Voyager on Neptune. And we are trying to observe as many of these as possible, because we think they're kind of like the Great Red Spot that's on Jupiter, like a big storm system that creates lots of changes in the atmosphere, in all levels of the atmosphere. And it's still unknown as to how a dark spot changes the upper levels and, and changes the chemistry and the circulation going on.

Naomi Rowe-Gurney: So that's a major thing that the JWST is going to be looking at, because we’re using the mid-infrared in with JWST. And the mid-infrared is really interesting because it senses a little bit higher up than those visible and near-infrared wavelengths in the stratosphere. And that's where all of that interesting chemistry is going on that I was talking about. And that we think is also being affected by these dark spots that might be these circular storms that are happening.

Naomi Rowe-Gurney: And that's actually what my PhD was looking at with Spitzer. But the problem with Spitzer is that it's so small, it's only like naught-point eight five [0.85] meters in diameter, so less than, less than a meter and…

Jim Green: The telescope mirror itself.

Naomi Rowe-Gurney: Yeah, exactly. And that's actually the same size as the secondary mirror of the JWST. So the mirror that is used to focus the big 6.5-meter mirror is the same size as the Spitzer's major mirror. So.

Jim Green: Wow. Yeah, that's a good metric. (laughs)

Naomi Rowe-Gurney: Yeah, right? That is a massive advantage. Because with Spitzer, we didn't have any images, because they're so far away, both Uranus and Neptune are so far. And they're also quite cold, it means that we only had like a point of light. So we can look at it like we look at a star in the night sky. That's how far away they are. And all we get is one spectrum. So one piece of light for just the whole planet.

Jim Green: So Hubble has been observing Uranus and Neptune. But there are specific proposals that come in and do that. Have you been involved in any of those?

Naomi Rowe-Gurney: Yes. So just recently, in fact, today, this morning, I found out that one of my proposals that I sent in to observe the ice giants is has been approved on HST 30. So cycle 30, which is really, really exciting, like Hubble Space Telescope is amazing. It was launched in 1990. And actually, that makes it the same age as me, which always makes me feel very, both old and also very young. (laughs)

Jim Green: Yes, indeed!

Naomi Rowe-Gurney: Yeah! So yeah, my project is going to be using Hubble to look at Uranus and Neptune to kind of increase the science that we have for, with the JWST. So it's going to be looking at them, hopefully as close as possible to the JWST observations. And that will mean that we are getting even more wavelengths in there because JWST is looking at the mid-infrared, and near-infrared, but Hubble has capabilities all the way down to the visible, which is really exciting because using visible and also some of the near-infrared. So we can expand that that window and also the depths that we're looking at in the atmosphere.

Jim Green: Wow, perfect.

Jim Green: You know, one of the things that really fascinated me about Uranus and Neptune is the heat that they produce. You know, all our planets are hot on the inside, they're still cooling off from when they were made 4.6 billion years ago. But Neptune, correct me if I'm not right, is producing more heat on the inside than Uranus is. Do we know what's happening?

Naomi Rowe-Gurney: That's true. So it's actually Uranus that's the weird one. Neptune is, is creating the amount of heat on the inside that we would expect a planet to make.

Jim Green: Ah, thank you for correcting me, yeah.

Naomi Rowe-Gurney: Just like on Earth, we have like things like the mantle happening inside. It's like the remnant of the, the creation of the planet is still hot on the inside and it's only very slowly cooling down. And that's what we expect to see with all of the other planets as well — a hot interior leftover from creation. And that's not what we see at Uranus. We see a negligible internal heat. So it looks like there's no internal heat really going on at all inside. And that's very strange. And one explanation is that Uranus was hit by something really big, and kind of turned inside out. And all of that internal heat got lost.

Naomi Rowe-Gurney: And that would also explain why the planet is on its side, which is also another weird and very unique thing in the solar system. No other planet is just on its side spinning, like, on its axis in the wrong direction.

Jim Green: That's fantastic. Well, you know, we've been looking at planets beyond our own in our own solar system, and Kepler came out with some amazing results. And those results indicated the distribution of planets that we see in other solar systems. And I always thought, “Oh, well, we got to be seeing oh, you know, a bunch of Jupiter's.” but it turns out Jupiter's now you know, big Jupiter's are not one of the common planets. But indeed, more of what we call Super Earths, but also mini-Neptune. And so the ice giants Uranus, and Neptune hold a really special place in terms of how important that might be for other solar systems. What can you tell me about those kinds of capabilities?

Naomi Rowe-Gurney: Yeah, so that's a major motivation behind looking at our own ice giants and why the entire planetary science community and science community is so interested in both of these planets now, it's because we found so many of these Neptune-sized or Uranus-sized, just ice giant sized planets in other solar systems. And we can look at our own ice giants and try and understand a little bit more about how they're formed, and their place in our solar system and how they got there. And that will give us a massive insight into these other solar systems that we're seeing.
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Odp: [NASA Gravity Assist] : Season 5
« Odpowiedź #56 dnia: Wrzesień 10, 2023, 07:46 »
Gravity Assist: It’s Raining Diamonds on These Planets (2)


Naomi Rowe-Gurney is a postdoctoral research associate at NASA's Goddard Space Flight Center through Howard University. Credits: Lydia Neary

Jim Green: You know, right after Webb’s launch on December 25, man, you must have been busy!

Naomi Rowe-Gurney: Yeah, so straight off the launch, I didn't have too much to do with launch. That was all the engineers and ESA doing all of that. But then after that first stage, we did deployment. That was like the first phase of commissioning is what we call it. This phase, this six-month phase, getting the telescope ready for science is called commissioning. And so that first stage was deployment, getting the telescope through to the L2 Lagrange point, which is where it all bits, which is 1.5 million kilometers away from here to make sure that the telescope’s nice and cold, so they can see everything that it's looking at in its infrared images.

Naomi Rowe-Gurney: And then after that, when it reached there and deployed successfully, then after phase two, is the telescope alignment. So where it made all of these 18 separate movable segments into one seamless, like, giant 6.5-meter mirror. And then the third stage is the stage that I've been involved in, which is the science instrument commissioning. And I've been involved in a team called the Moving Target Vommissioning Team. And that means that we have been looking at asteroids. So asteroids that are in that asteroid belt mostly, and making sure that the telescope is able to track things that are moving, because everything in the solar system compared to distant objects is a moving target. And it means that the telescope actually has to move physically as it is looking at these objects. And that is definitely needed for everything in the solar system. So that's what we've been testing in this last phase, and then that will be over soon. And then those first images come out on the 12th of July, which is very exciting.

Jim Green: So the first light science from JWST is going to be shown July 12. And then from then on, we're going to see all kinds of fantastic stuff coming out in this regular schedule that it has. So when will Webb start looking at solar system objects?

Naomi Rowe-Gurney: So it won't be part of those first images that come out on the 12th of July. But we will actually start to look at solar system objects. It's just those images won't be released to scientists until after that 12th of July date, and then they won't be released as, kind of, science or anything until our scientists have done their analysis and calibration and everything. So probably, we'll see those first things come out at the end of the summer, I would say, is optimistic.

Jim Green: Now, one of your jobs is, you’re a JWST Solar System ambassador.

Naomi Rowe-Gurney: Yes.

Jim Green: So tell me what that's all about? And what are you doing?

Naomi Rowe-Gurney: So I help everybody who has guaranteed time observations, which means observations in this first year of the James Webb's lifetime. And so everybody who is using JWST to look at solar system objects, or at planetary systems. So all four giant planets, Mars, also the rings, and all of the moons as well. So those ocean worlds and Titan and icy moons, and smaller moons as well of Saturn we're going to be looking at. And I am there to kind of assist people in going from data all the way through to getting their science published. 

Jim Green: Well, so you'll be right on top of some of the latest discoveries.

Naomi Rowe-Gurney: Yeah, I hope so.

Jim Green: Wow, that's fantastic. I know this is going to be such an exciting time for our scientists, and for NASA with a telescope so large, looking at wavelengths that we cannot see from the ground. Well, Naomi, I always like to ask my guests to tell me the person, place or event that propelled them to become the scientists they are today. And I call that event a Gravity Assist. So Naomi, what was your Gravity Assist?

Naomi Rowe-Gurney: My gravity assist was an event-slash-place. It was when I was about five years old, I went to the planetarium in London. And I hadn't really thought about Earth or space or anything like that before then. And it just completely opened my mind. And I was just obsessed with space ever since then. And I loved cosmology, and astrophysics and planetary science and even Earth science. I was just obsessed with it. And I went through my entire school life, loving science, being terrible at math, but going through it just because I really wanted to do science. And obviously getting to where I am today, because of that first, yeah, gravity assist from the planetarium in London. So, love them.

Jim Green: Wow, that's, that's really neat. And I have to comment on your math mention, because there's so much different types of math. You know, not all math is created equal, so to speak.

Jim Green: I was horrible in geometry. I just did not like it. But I mean, give me a differential equation, and I'll solve it.

Naomi Rowe-Gurney: I’m the same. I hate numbers. I still count on my fingers because numbers just don't make sense to me. So I'm great at algebra, though. So yeah…it’s all different types of math, so...

Jim Green: It is, it is. So I always encourage, kids in school to look past that not to be discouraged, because they have trouble in one area of math, because they'll find out that in the end, the kind of math that they can really get into will help them be the scientists that they are, or the engineer that they are, in their future life.

Naomi Rowe-Gurney: Definitely.

Jim Green: So, so those challenges are important to overcome.

Naomi Rowe-Gurney: Yeah, I would say my advice would be: Don't listen to people when they say that you can't do something. I had so many teachers and tutors, and just people in my life that said, “Maybe you should do something a bit easier. Maybe you should, I don’t know, like, pick a different subject. Maybe maths isn't for you, you know, maybe science is a little bit hard, like try doing something else. And I'm really glad that I didn't listen to them. And I let my heart decide that even if it was hard, I was going to try. And I thankfully have a very supportive family that were always very supportive of me.

Jim Green: Well, Naomi, thanks so much for telling us about that fantastic science of these gas giants. And the JWST is going to give us so much more information about them.

Naomi Rowe-Gurney: Thank you so much for having me. This has been great.

Jim Green: Well join me next time as we continue our journey to look under the hood at NASA and see how we do what we do. I'm Jim Green, and this is your Gravity Assist.


Credits
Lead producer: Elizabeth Landau
Audio engineer: Manny Cooper
Last Updated: Jul 1, 2022
Editor: Michael Bock

Source: https://www.nasa.gov/mediacast/gravity-assist-it-s-raining-diamonds-on-these-planets
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Odp: [NASA Gravity Assist] : Season 5
« Odpowiedź #57 dnia: Wrzesień 17, 2023, 08:55 »
O sztuce transformacji surowych danych zebranych przez instrumenty teleskopu na postać wizualnie fascynującą.
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Joe DePasquale: And for the 28th anniversary, we looked at the Lagoon Nebula and produce this like beautiful multicolor image in narrowband wavelengths.

Joe DePasquale: So what I was saying before about red, green, and blue, those are sort of wide bands. Hubble has filters that look in like wide swaths of the spectrum. But it also has these filters that are attuned to very specific wavelengths and very narrow regions within those wavelengths. And so that image is actually a combination of three narrowband wavelengths in red, green and blue, that just produce this amazingly detailed tapestry of gas and dust and star formation.

Gravity Assist: How We Make Webb (and Hubble) Images (1)
Jul 8, 2022


This colorful image, taken by the Hubble Space Telescope, gives us a window seat to the universe’s extraordinary stellar tapestry of birth and destruction. At the center of this image is a monster young star 200,000 times brighter than our Sun that is blasting powerful ultraviolet radiation and hurricane-like stellar winds, carving out a fantasy landscape of ridges, cavities, and mountains of gas and dust. Credits: NASA, ESA, and STScI

The world will get a first glimpse of the universe as never before when the first images from the James Webb Space Telescope come out on July 12. And this is only the beginning — the telescope will deliver all kinds of insights about galaxies, planets, and more, for years to come. But someone has to translate that data into beautiful imagery, especially since Webb collects light that falls outside of human vision. That’s where Joe DePasquale of the Space Telescope Science Institute comes in. Learn how he makes choices about color and other aspects of space images in this week’s Gravity Assist podcast.

Jim Green: In just a few days, we're going to see the first images that came from the James Webb Space Telescope. Let's talk to somebody that's worked to make these beautiful images come to life.

Joe DePasquale: The images are spectacular. They're gonna blow people away.

Joe DePasquale: There's sort of like a universal appeal to these images. They touch on a collective need or want to understand the deeper questions of the universe that we all have, in ways that connect us all together.

Jim Green: Hi, I'm Jim Green, and this Gravity Assist, NASA’s interplanetary talk show. We’re going to explore the inside workings of NASA and meet fascinating people who make space missions happen.

Jim Green: I'm here with Joseph DePasquale and he is the senior data image developer in the Office of Public Outreach at the Space Telescope Science Institute in Baltimore, Maryland. Joe has worked on bringing spectacular space images to life from missions like Hubble and Chandra. But now he's working with the James Webb Space Telescope group, which will be unveiling its first images on July 12th. So welcome, Joe to Gravity Assist.



Joe DePasquale is a senior data image developer in the Office of Public Outreach at the Space Telescope Science Institute in Baltimore, Maryland. Credits: STScI

Joe DePasquale: Hi, Jim, thanks for having me. I'm really happy to be here.

Jim Green: Well, you know, a lot of people probably don't realize that when we look at a Hubble image, that it's not exactly what the spacecraft sees. You know, someone such as you has to serve as that intermediate process between the data and the final image and make decisions on how to make that image pop. So how would you describe what you do?

Joe DePasquale: Well, like you said, Jim, it's, the telescope is not really a point and shoot camera. So it's not like we can just take a picture and there we have it, right? It's a scientific instrument. So it was designed first and foremost, to produce scientific results. It just so happens with Hubble, and with Webb, that these instruments are exquisitely sensitive, and they create beautiful images of the universe. But it's scientific data first, so we have to take that data and convert it into an image. And that's, that's where I come in, myself and my colleague, Alyssa Pagan.

Jim Green: All right, well, what kind of training do you have, that really has enabled you to take these images and make them shine?

Joe DePasquale: Yeah, that's an interesting question. My, my career path has kind of meandered through my life. But, I started out with a degree in astronomy and astrophysics. And I worked for eight years for the Chandra mission as a data analyst, in calibration for the telescope, one of its detectors.

Joe DePasquale: And during that time, I learned a lot about how the images from Chandra were made, and how to create color images from the data. And it was sort of a natural transition from that position into public outreach for Chandra, creating, like press imagery from the data. So my background was really in astronomy, but also, I've had a lot of interest in like arts, painting, you know, photography, color theory, and like all of these interests sort of come together to be able to allow me to, you know, have the skill set needed to make these images.

Jim Green: Yeah, I think you point out a really an important aspect about it. And that is, having that science background already gives you the intuition as to what that image is all about. As you say, you paint?

Joe DePasquale: Right.

Jim Green: So in addition to having that science background, you have that artistic flair, now I don't have much of an artistic flair. (laughs) So it takes a really unique individuals to do that. But that science background is really key, I think. So when you get that image from a spacecraft, what does it look like? Is just a bunch of ones and zeros? And how do you turn them into the beautiful things they are?

Joe DePasquale: (laughs) Yeah, so the data do come down in a digital format of ones and zeros, although the raw data that we get from the archive is, you know, it's a black and white image, essentially. It's basically just the brightness levels of the pixels that the detector saw. So it was sitting in one spot looking at some object in space collecting light. And the image that we get is, sort of, that raw image from the detector. And it needs a lot of work to be able to even see what's in the image. We have to do something called stretch the data, and that is to take the pixel values and sort of reposition them, basically, so that you can see all the detail that's there.

Joe DePasquale: If you don't do that, it basically looks like a black image with some white specks in it, because there's such a huge dynamic range. And what I mean by dynamic range is just the darkest darks and the brightest whites in the image. The whites are super bright and they stand out as these white specks, but all of the other material and interesting stuff is sort of buried in the dark regions of the image. And you have to bring it out without oversaturating it.

Jim Green: Got it.

Joe DePasquale: So if you bring everything up equally, then you're, you're bringing up all that dark information, but you're also over saturating the bright. And so there's a compression that happens, that allows you to retain the information that's bright, but also bring up the dark parts of the image.

Jim Green: Well, you know, our eye has is so fantastic, a tool for us to see a very broad range of wavelengths. And, and our eye is sensitive more in certain colors than in others. Does that affect how you actually end up picking the colors and repainting the image?

Joe DePasquale: Yeah, that's very true. So our eyes, you know, they have cone cells that are sensitive to colors of light, and nominally, red, green, and blue. And so we use that that sort of biology of the eye as a framework within which to apply color to the images.

Joe DePasquale: When we're working with Hubble, and Webb, or even Chandra, even wavelengths that are beyond what we can see with our eyes, we use a technique called chromatic ordering to the data. And what that means is that, for Hubble, it looks in very specific wavelength ranges. So we have these filters that filter out light, and allow you to see like, if you were taking an image in red light, the filter filters out everything but red, and allows you to see an image in just red light. Of course, it comes down to us black and white, and we have to later apply that color red to it.

Joe DePasquale: But our color images are made up this way by taking red filters and coloring them red, green to green and blue to blue. When you move away from red, green and blue, like visually, we use this same approach. So for example with Webb, if we take short-wavelength infrared light and assign blue to that, and then as you move into the longer wavelengths, you go from blue to green to red, that's what I mean by chromatic ordering.

Jim Green: Yeah, so you, you actually use as your color palette the spectrum of light, as we break it up in a prism. So it has that specific ordering associated with it.

Joe DePasquale: Yeah, that's right. The red, green, and blue primary colors, you know, within those, you can have all the colors of the rainbow.

Jim Green: Yeah, to me that's really important to understand. So it's not like, “Oh, I'm gonna take this and make it purple. And then right next to that, we're going to make this yellow.”

Joe DePasquale: That's right, yeah, you're absolutely right, that we're not going in there and applying like painting color on to the image. We are respecting the data from beginning to end. And we're allowing the data to show through with color. So if you look at a galaxy, for example, in optical light, the regions of the galaxy where there's active star formation, we expect those to be sort of glowing in hydrogen, which would be red.

Joe DePasquale: And so we know that when we use that red filter, and it's colored red, you apply red, green, and blue together, you're going to see like a highlight in red where there are star forming regions. So there's actually a lot of science that you can learn just by looking at the color image.

Jim Green: So Joe, after you get that initial image that you feel just is right, and it has the, the look and feel about it that really makes the observations in the data pop, is there an interaction period with the scientists about that? And do you then go back and modify that?

Joe DePasquale: Yeah, Jim, it's very much an iterative process. But I do feel like over the years, I've sort of honed my intuition into what looks good. So you know, the initial starting point is always like the springboard for the discussion.

Joe DePasquale: But we do have a lot of back and forth with the scientists that we work with on these images, specifically, to help really bring out the details that they want to specifically bring out for their particular results, their science results. You know, that may require a little extra work here or there, just to get that thing to pop a little more.

Jim Green: Well, what's been some of your favorite images to work on from Hubble?

Joe DePasquale: So every year we do an anniversary image, right, where we pick an object that we know is going to be pretty spectacular when viewed with Hubble. And we'll do an anniversary image release to celebrate the launch of Hubble.

Jim Green: Cool!

Joe DePasquale: And for the 28th anniversary, we looked at the Lagoon Nebula and produce this like beautiful multicolor image in narrowband wavelengths.

Joe DePasquale: So what I was saying before about red, green, and blue, those are sort of wide bands. Hubble has filters that look in like wide swaths of the spectrum. But it also has these filters that are attuned to very specific wavelengths and very narrow regions within those wavelengths. And so that image is actually a combination of three narrowband wavelengths in red, green and blue, that just produce this amazingly detailed tapestry of gas and dust and star formation.

Jim Green: Well, you've also worked on Chandra.

Joe DePasquale: That’s right.

You know, and although Hubble does observe in the visible light in the light that we can see, and a little bit into the infrared in the light, we can't see, Chandra, we can't see any of that data from the ground and from our eye.

Jim Green: Right.

Joe DePasquale: So what do you do with that data in tell us about your favorite image?

Joe DePasquale: Yeah, so that's a really interesting challenge when you're talking about X-ray light, because it is beyond human vision, right? So we like to in the, you know, imaging community in astrophotography like to refer to this process as “representative color,” instead of what it used to be called, are still many people call “false color images.” I dislike the term “false color,” because it has this connotation that we're faking it, or it's, you know, this isn't really what it looks like, the data is the data. That's, that's exactly what it looks like.

Jim Green: Yeah. And as you said, you're keeping true to that data from a scientific perspective by connecting the colors in the right way.

Joe DePasquale: Right.

Jim Green: …with the wavelengths.

Joe DePasquale: Yeah, so and a good example of, you know, working with multi-wavelength imagery, combining Hubble and Chandra, one of my favorite images that we worked on was the Antennae Galaxies, where we have these two interacting galaxies, they're sort of playing, dancing around each other, and merging together. And that image actually also included infrared data from the Spitzer Space Telescope. And in order to keep everything sort of very cleanly separated, I chose very specific colors for the different wavelengths in that image.

Joe DePasquale: And you know, that there's a Hubble image there of the Antennae galaxies that on its own is a beautiful, like, very detailed color image, I felt a little bad about the fact that I had to reduce its color from, you know, the beautiful three color image all the way down to just one color, which I colored gold in that version. And then I pulled the Chandra data in, in blue, and the infrared in red. And although each one of those on their own, it's, it's kind of like missing something, when you pull them all together, and they each have their own color, there's actually a wealth of information that you can pull out of that, that you wouldn't get from any one of them alone.

Jim Green: So what was it like working on this Webb data? Because it's now taking this data, it's now coming in, you're now having your hands on it. You're the one that knows what's being done, right?

Joe DePasquale: Yeah, that's right. (laughs) I can't speak in detail about it. But I can say that the images are spectacular, they're gonna blow people away.
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Odp: [NASA Gravity Assist] : Season 5
« Odpowiedź #58 dnia: Wrzesień 17, 2023, 08:55 »
Gravity Assist: How We Make Webb (and Hubble) Images (2)


The Antennae galaxies, located about 62 million light years from Earth, are shown in this composite image from the Chandra X-ray Observatory (blue), the Hubble Space Telescope (gold and brown), and the Spitzer Space Telescope (red). The Antennae galaxies take their name from the long antenna-like "arms," seen in wide-angle views of the system. These features were produced by tidal forces generated in the collision. Credits: X-ray: NASA/CXC/SAO/J.DePasquale; IR: NASA/JPL-Caltech; Optical: NASA/STScI

Jim Green: Good.

Joe DePasquale: Being among the first people to work on, it has been such a privilege. I feel like I have to pinch myself. Like, I can't believe that. I'm here at this moment in time, working at Space Telescope, working on the Webb project, pulling together the first data that Webb has taken and turning it into these beautiful color images, is just the highlight of my career right now.

Jim Green: When scientists look at their archive and get the data, you know, how important are these beautiful images that you create to them?

Joe DePasquale: I'd say it has grown in importance over the years. I believe that, know, scientists have their own ways and preferred ways of processing the data to pull out the details that they want to see. But ultimately, when they want to win, if they have newsworthy results, they want to present that in the best way possible. And that's where, you know, the work that I do comes in, where I can take something that they may have made, and you know, clean it up and turn it into something that's just a beautiful image, but also tells the story of their science and their results, as well as, you know, presenting a beautiful image.

Jim Green: Well, you know, space images are not only great for scientists. They're wonderful for the public. And I see Hubble images on all kinds of stuff, T-shirts, lunch box[es], posters, all kinds of other places. I mean, you know, in this area [near Washington, DC], you can go to the Dulles Airport, and if you take the underground walk from the parking lot, one and two, over to the airport, you see the beautiful wall of Hubble images, I don't know if you have done that. But but you know, millions of people have probably made that walk. So what does that feel like to see those images that you've worked on being displayed all over the world?

Joe DePasquale: It feels humbling, I will say, to know, that, like, work that I have done has been seen by millions of people, and is hopefully inspiring people to be like the next generation of scientists and engineers and maybe image processors. (laughs)

Jim Green: Sure.

Joe DePasquale: There's sort of like a universal appeal to these images. They touch on a collective sort of need or want to understand the deeper questions of the universe that we all have, in ways that connect us all together. You know, Carl Sagan was always a fan of saying that we are star stuff. And I always like to extend that to the fact that like, when we're observing the universe, when we're looking at these images, we are the universe thinking about itself. Right? So we're all connected. And this brings us all together.

Jim Green: So Joe, do you own any clothing with the images that you've made on it?

Joe DePasquale: (laughs) I personally don't own any clothing with my images on it. But my wife has a dress with one of my images on it, or actually the way it was put together. It's like sort of a mishmash of a couple different images. But something that I worked on is in there. I do have a pair of socks with the Webb telescope on them. So I frequently wear those for good luck.

Joe DePasquale: I remember when I was in college, sitting in class looking at we had a poster of the Pillars of Creation image, the famous Hubble image, right?

Jim Green: Yeah.

Joe DePasquale: And yeah, that was like hugely inspiring for me just sitting there wondering about like, even just how was this image made? Like, how was that actually there? How can we get a picture in such detail and clarity of this object? So that was a huge inspiration for me. And, you know, this is a bit of an aside. But when I started at Space Telescope, I actually worked with Zolt Levay for the first year that I was here, he was the original image processor for Hubble, you know, worked on many of these images that, you know, inspired me to get into astronomy in the first place. And I got to share an office with him for a year. So that was really special time. Yeah.

Jim Green: Well, you're really touching on the next thing I want to talk about. And that is, I always like to ask my guests to tell me, you know, the person, place or event that propelled them forward to become the scientists they are today. And I call that a gravity assist. So Joe, what was your gravity assist?

Joe DePasquale: Ah, that's a great question. So I think I have to go all the way back to high school. And, you know, knowing that I always was interested in astronomy and space and just looking up, and look at the stars and wonder what was up there. But I kind of lost a little bit of that through high school. And then I saw the movie “Contact” the summer before I started college. Right?

Jim Green: Ah, interesting! Uh huh!

Joe DePasquale: And I read the book, Carl Sagan’s book, and it just opened my eyes to the possibility of, like, pursuing a career in astronomy, and seeing what that could be like. And I switched my major that summer, right before I started school, I switched into astronomy. I went to Villanova University, which has a wonderful undergraduate astronomy program school.

Jim Green: Yeah. Good school.

Joe DePasquale: Yeah. And, you know, the rest is history. That was sort of the thing that got me going. I would call that my gravity assist.

Jim Green: Yeah, yeah, I would too, I would too. Well, for me in high school, I had the privilege of working on a 12-inch Alvan Clark refractor that was associated with the high school, and it was part of what was called the Witte observatory. So I caught the bug like you did early on in my career, and that really set the tone to move forward.

Joe DePasquale: That’s great.

Jim Green: Well, Joe, thanks so much for telling us about the process of making these fabulous images from the NASA telescopes.

Joe DePasquale: Thank you, Jim. Glad to talk about anytime. (laughs)

Jim Green: Well join me next time as we continue our journey to look under the hood at NASA and see how we do what we do. I'm Jim Green, and this is your Gravity Assist.


Credits
Lead producer: Elizabeth Landau
Audio engineer: Manny Cooper
Last Updated: Jul 8, 2022
Editor: Gary Daines

Source: https://www.nasa.gov/mediacast/gravity-assist-how-we-make-webb-and-hubble-images
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Odp: [NASA Gravity Assist] : Season 5
« Odpowiedź #59 dnia: Wrzesień 24, 2023, 14:23 »
Dla przypomnienia, dlaczego JWST ma tak duże znaczenie.
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John Mather: Kiedy mówiliśmy o zdjęciu Hubble'a, Głębokie Pole Hubble'a było świetne, ale niewystarczająco. Spodziewaliśmy się, że rzeczy znajdujące się najdalej będą najtrudniejsze do zobaczenia. Będą to po prostu najmniejsze plamki w podczerwieni . A teraz teleskop Webba może je zobaczyć i powiedzieć, co w nich jest? Jakie są składniki chemiczne tych małych plamek? Oraz jak daleko sięgają w czasie? Maleńkie czerwone plamki – cóż, nawet teleskop Webba nie jest w stanie zbyt dobrze dostrzec ich kształtów. Ale możemy zobaczyć, że tam są i zobaczyć, z czego są zrobione. Możemy je policzyć i zobaczyć, ile.

Gravity Assist: Meet a Webb Scientist Who Looks Back in Time (1)
Jul 29, 2022


Dr. John Mather, the senior project scientist on the James Webb Space Telescope, has been working on the observatory for more than 25 years. Credits: NASA/Chris Gunn

The James Webb Space Telescope awed the world on July 12 with its first images and data. And it’s just getting started with its exploration of the cosmos. Dr. John Mather, the observatory’s senior project scientist, has been working toward this milestone for more than 25 years. Before Webb, he worked on a spacecraft that delivered a groundbreaking baby picture of the universe and offered the best evidence yet that the universe began with a rapid expansion we call the big bang. Dr. Mather describes some of the first images and explains the mysteries that Webb will tackle.

Jim Green: We just saw spectacular images from the James Webb Space Telescope. Let's talk to an expert and find out all the other things that it can do.

John Mather: Everything from here in the solar system all the way out as far back as you can possibly go in time to tell the story of the universe, how did it go from the big bang to people?

Jim Green: Hi, I'm Jim Green, and this Gravity Assist, NASA’s interplanetary talk show. We’re going to explore the inside workings of NASA and meet fascinating people who make space missions happen.

Jim Green: I'm here with Dr. John Mather, and he is the senior project scientist for the James Webb Space Telescope, which of course, just released its first spectacular images earlier this month. John is based at NASA's Goddard Space Flight Center in Greenbelt, Maryland. Welcome, John, to Gravity Assist.

John Mather: Thank you, Jim.


Dr. John Mather, an astrophysicist at NASA’s Goddard Space Flight Center, won a Nobel Prize for his work on the COBE satellite. COBE measured the light left over from the big bang, shown in this map. These minute temperature variations (depicted here as varying shades of blue and purple) are linked to slight density variations in the early universe. Credits: NASA

Jim Green: It's really an honor to have you here. And I know you've had a long career at NASA much like I have, and experienced so many fantastic things. And so I'd like to talk about a couple of them. One of which, of course, is COBE. This was one of your first major missions, and of course, in a wonderful way that led to your Nobel Prize. So can you give me a little background about COBE?

John Mather: Sure, well COBE was the Cosmic Background Explorer satellite, and it was proposed back in 1974, to measure the big bang . So what's it mean to measure the big bang? It means measure the cosmic microwave background radiation, which fills the entire universe now. And is evidence of the conditions at the very earliest moments, whatever they were. So task number one, see, is it the right color? Is it colorless in the sense of matching up a theoretical curve called a black body spectrum? And, and it is. Number two, is it the same in every direction? And the answer is almost, but not quite. And that's really important because we interpret the hot and cold spots that we saw on the map, to say those come from the big bang itself, whatever the big bang really was. And they made the universe not exactly smooth and not exactly uniform, and because of that we are here.

John Mather: So when we showed the map to the to the world, Stephen Hawking said “Well, that's the most important scientific discovery of the century, if not of all time!”

Jim Green: (laughs)

John Mather: Oh, okay, Stephen, why is that so important? Well, number one, we think that gravity acting on those primordial spots was able to turn around the expanding universe in places and cause the formation of galaxies and stars and eventually leading to planets and people. So we're here because of that. Number two, most of those spots are coming from something astronomers had recognized, but nobody can see. It's called cosmic dark matter. And so, okay, so we now are able to measure the cosmic dark matter by its effects on that map. And, number three, the pattern is affected somewhat by the cosmic dark energy, which also astronomers can detect but cannot see. So that tells us the expansion history of the universe. That's pretty important to our story. And finally, if we ever could figure out what made this spots, we would be thrilled because it would tell us something about quantum gravity, which is one of the biggest open questions of physics today.

Jim Green: Did COBE prove the big bang happened? Or were there some sort of indications prior to that?

John Mather: Nothing can actually prove the big bang, we can always disprove something. So there was one major alternative theory to the we call the big bang the expanding universe, and it was called the steady state theory. And it had some very strange and interesting predictions, but it was definitely not in agreement with observations after we got them with the COBE satellite. So the big bang or the expanding universe, as I call it, is the remaining theory. What's interesting is what was it like in the very earliest moments? So we can still argue a lot about what happened when the temperature was incredibly high, and the density was incredibly high. But there was something extreme in those first sub-microseconds, and that's what I call the big bang

Jim Green: Well, what is happening in the early part of the universe that James Webb is going to be able to tease out? You know, it looks in the infrared and also looks back in time!

John Mather: Well, the Webb telescope does look back in time by looking at things that are far away. Light takes a long time to get here from there. So we can look back on not quite all the way towards the beginning. But if nature gave us an object to look at, then we should be able to see it as soon as 50 or 100 million years after the expansion started up. So those primordial objects are purely predicted at the moment. Nobody's ever seen them. But we built the Webb telescope so that we could if they are there.

John Mather: By the way, when we’re talking about the size of the universe, the universe as a whole is probably infinite, so it doesn't really have a size. The part that we can see is 13.7 or 13 point 8 billion light-years in dimension at the moment, or it was when the light was sent to us. So that's a little tricky bit too, because of course, everything's been moving and changing ever since the light came.

John Mather: But in any rate, our job with the Webb telescope is looking as far back towards that moment to into what we call the Cosmic Dark Ages, to see the first luminous objects that grew out of that primordial material. So they could have been stars, they could have been galaxies that came together, before the stars grew, they could have been black holes, there even are stories about how black holes could grow out of that primordial material. It's even logically possible that there are some left from the big bang itself. Although nobody has figured that one out, we've never seen a real signs of them. But what about that? So that's sort of number one cosmological objective is to see back as far as possible in time.



NASA’s James Webb Space Telescope revealed never-before-seen details of galaxy group “Stephan’s Quintet” in this image. Credits: NASA, ESA, CSA, and STScI
https://www.nasa.gov/webbfirstimages

Jim Green: It really sounds to me, like you as cosmologists are following a series of missions that then build on one another. How did you personally go from working on COBE to then getting involved in the James Webb Space Telescope?

John Mather: Well, it was not my plan, actually. Somebody else was already working on this new telescope concept. And COBE was more or less done. And I think, “what am I going to do next that’s as good as that?” And I got a phone message from NASA Headquarters, from Ed Weiler and “we're going to start a study of this new telescope, do you want to work on it? And if we do, then I need a proposal from you tomorrow.”

Jim Green: (laughs)

John Mather: So he knew that he had something to push and that it was time to start. So of course, I called up the people they told me to talk to and we sent in the proposal, and we got rolling. So I had no idea how hard this mission would be, or how long it would take. But I just could tell this was the most important thing I could possibly be working on, as a follow up to the COBE satellite.

Jim Green: What was the original questions that you were scientifically trying to answer with this new telescope that you were conceptually working on?

John Mather: Well, right away, we knew there were many questions it could answer because it would be doing something no one ever could ever possibly do in any other way. We knew we needed an infrared telescope. So why infrared? Well, number one, it's now technically possible. And it's never been possible before. Because we have the in the capability of cooling things down, we have the capable amount ability of launching a telescope into space that would be much larger than ever we tried before. And the Hubble can't do it. Because the Hubble emits infrared light. The ground telescopes can't do it because they emit infrared and the sky is kind of dark or bright or opaque one way or the other. So you can't do it from here. So this is all going to be a big mystery until we can get telescopes into space to do this work.

John Mather: So what are you going to be able to do not only look back and farther in time, but also look inside and dust clouds where stars are being born today. We didn't even know yet there would be so many planets at the time. In 1995, just we were just discovering the very, very first planets around other stars. So now we know most stars have planets and we did make a few adjustments to the mission concept so we could study them too.

John Mather: So anyway, basically everything from here in the solar system all the way out as far back as you can possibly go in time to tell the story of the universe, how did it go from the big bang to people?

Jim Green: It's going to be an amazing story as we put in more of the puzzle pieces, and figure out what's happening. Well, did Webb originally have these big mirrors that were segmented? Or was it you know, what, what was the original thought? How do you compare those early concepts with what we have today?

John Mather: Early concepts actually resemble the one we have today very closely.

Jim Green: Really? Wow!

John Mather: There were different ways you can fold up the segmented telescope. But we knew right away, we had to have a big sunshade because the telescope has to be cold. We knew we couldn't keep the telescope near Earth. Because the Earth is always warm, and it's always getting in the way. So you couldn't keep the telescope cool near Earth. Okay, push it far away, where's the next place to go? It's called the Lagrange point 2, it's a million miles out there. But it's a great place if you can get there. On the other hand, “if you can get there” means “use a rocket you can get.” And that means the telescope is going to be pretty different. It's going to be ultra-light, the mass of the telescope is half of what the Hubble was, is.

Jim Green: Wow.

John Mather: It's a huge challenge. But the basic sketch that we drew is pretty similar to what we actually flew.

Jim Green: So John, as you're going along, helping put this telescope together, when did it happen that you thought, “hey, we've turned the corner, and this is gonna work!” Did that ever occur?

John Mather: I think I always knew this was going to work.

Jim Green: (laughs)

Jim Green: And the reason for that is, we have a brilliant engineering system for keeping track of everything that might go wrong. And if anybody has a worry about it, they speak up. And we talk about it and make sure we fix whatever that was. And so from the beginning to the end, we've had project managers and support from NASA Headquarters that said, “Yeah, that's the right thing to do.” We're not cutting corners on this, we're going to do it right. So, on the other hand, I was just sitting there quite calmly at launch, and I was just happy to watch it go up. Now, when we finally got to the image release, oh, my gosh, all the things that could go wrong, suddenly, they come flooding into my mind and this is like, I've been walking along the edge of a cliff for 25 years, and I didn't fall off.

Jim Green: I mean, we were all waiting in bated breaths for July 12 to come around. And, and I have to tell you, I was just blown away. And I'm sure you felt that, too. So what were some of your impressions when you first saw this data coming in?

John Mather: Well, my goodness, I was like, almost everybody else. I had not seen them until they were polished. And so we went from, more than two decades of “is it really going to work?” to “it is so spectacular.” And the pictures are so beautiful. And everything we said we were going to do that seemed impossible, we're doing it.
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Odp: [NASA Gravity Assist] : Season 5
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