[NASA Gravity Assist] : Season 5

[Orionid]

jak poszukiwać technosygnatur na egzoplanetach ?

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!

[Orionid]

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

[Orionid]

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.

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.

[Orionid]

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

[Orionid]

Jak wyhodowano Arabidopsis thaliana z użyciem księżycowego regolitu.

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.

[Orionid]

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

[Orionid]

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


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

Source: https://www.nasa.gov/mediacast/gravity-assist-what-will-we-eat-on-mars

[Orionid]

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?

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.

[Orionid]

Gravity Assist: This is What Mars Sounds Like, with Nina Lanza
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

Source: https://www.nasa.gov/mediacast/gravity-assist-this-is-what-mars-sounds-like-with-nina-lanza

[Orionid]

Co słychać na Marsie?

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.

[Orionid]

Gravity Assist: It’s Raining Diamonds on These Planets
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

Source: https://www.nasa.gov/mediacast/gravity-assist-it-s-raining-diamonds-on-these-planets

[Orionid]

O nadziejach związanych m.in. z poszerzeniem wiedzy nt. Urana dzięki obserwacjom JWST.

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

[Orionid]

Gravity Assist: How We Make Webb (and Hubble) Images
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

Source: https://www.nasa.gov/mediacast/gravity-assist-how-we-make-webb-and-hubble-images

[Orionid]

O sztuce transformacji surowych danych zebranych przez instrumenty teleskopu na postać wizualnie fascynującą.

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.

[Orionid]

Gravity Assist: Meet a Webb Scientist Who Looks Back in Time
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

Source: https://www.nasa.gov/mediacast/gravity-assist-meet-a-webb-scientist-who-looks-back-in-time