Mars Reconnaisance Orbiter (MRO)

[kanarkusmaximus]

Ta wiadomość dotyczy tylko jednego z rodzajów wąwozów. Inne w skrócie zwane RLS są wiązane z wodą z powodu uwodnionych minerałów im towarzyszących

Tylko jednego z wąwozów? Z artykułu wynika, jak gdyby w ogóle był problem z wykryciem żlebów, gdzie są uwodnione minerały.

[Orionid]

Część Lethe Vallis z kanałem odpływowym. Zdjęcie zostało wykonano 6 maja 2016  przez Experiment High Resolution Imaging Science (HiRISE).

This image shows a portion of Lethe Vallis, an outflow channel that also transported lava. Another investigation of this area (Balme et al., 2011) discovered a repeat pattern of dune-like forms in the channel interpreted as fluvial dunes (or, giant current ripples) which are dunes formed by flowing water.

This is one of only a few places on Mars where these pristine-appearing landforms have been identified. The channel formed by catastrophic floods, during which it produced the prominent crater-cored, teardrop-shaped island in the middle. The island has the blunter end pointing upstream and the long tail pointing downstream.

Both the island and the fluvial dunes were formed by these extreme floods and their size is an indicator of the enormous discharges required to create them. The margins of the channel also show the terminal front of a pristine lava flow unit that inundated the channel from the south and the dunes show the remnants of another older lava flow. The top of the island displays polygonal patterned ground texture, which is a characteristic of periglacial processes in ice-rich ground.

The dark materials from the channel and island walls are probably dark sand being eroded from an underlying horizontal basaltic (lava) layer. The crater at the core of the island has elongated dunes and reticulate dust ridges inside. This single image thus contains features formed by periglacial, volcanic, fluvial, impact, aeolian and mass wasting processes, all in one place.

https://www.nasa.gov/image-feature/a-streamlined-form-in-lethe-vallis-mars

[Orionid]

Zbiorniki wodne  na Marsie mogły się tworzyć później niż do tej pory sądzono.

The recently discovered lakes and streams appeared roughly a billion years after a well-documented, earlier era of wet conditions on ancient Mars. These results provide insight into the climate history of the Red Planet and suggest the surface conditions at this later time may also have been suitable for microbial life.

"We discovered valleys that carried water into lake basins," said Sharon Wilson of the Smithsonian Institution, Washington, and the University of Virginia, Charlottesville. "Several lake basins filled and overflowed, indicating there was a considerable amount of water on the landscape during this time."
http://www.jpl.nasa.gov/news/news.php?feature=6619

[Orionid]

Pajęcze struktury  rejestrowane przez High Resolution Imaging Science Experiment (HiRISE).

The type of terrain called spiders, or "araneiform" (from the Latin word for spiders), is characterized by multiple channels converging at a point, resembling a spider's long legs. Previous studies concluded that this ground texture results from extensive sheets of ice thawing bottom-side first as the ice is warmed by the ground below it. Thawed carbon dioxide gas builds up pressure, and the gas escapes through vents in the overlying sheet of remaining ice, pulling dust with it. This process carves the channels that resemble legs of a spider.

"The trapped carbon dioxide gas that carves the spiders in the ground also breaks through the thawing ice sheet," Schwamb said. "It lofts dust and dirt that local winds then sculpt into hundreds of thousands of dark fans that are observed from orbit. For the past decade, HiRISE has been monitoring this process on other parts of the south pole. The 20 new regions have been added to this seasonal monitoring campaign. Without the efforts of the public, we wouldn't be able to see how these regions evolve over the spring and summer compared with other regions." 

Some of the HiRISE observations guided by the volunteers' input confirmed "spider" terrain in areas not previously associated with carbon dioxide slab ice.

"From what we've learned about spider terrain elsewhere, slab ice must be involved at the locations of these new observations, even though we had no previous indication of it there," Hansen said. "Maybe it's related to the erodability of the terrain."

http://www.jpl.nasa.gov/news/news.php?feature=6654

[Orionid]

The distinctively fluted surface and elongated hills in this image in Medusae Fossae on Mars are caused by wind erosion of a soft fine-grained rock. Called yardangs, these features are aligned with the prevailing wind direction. This wind direction would have dominated for a very long time to carve these large-scale features into the exposed rock we see today. The image was acquired at 15:25 local Mars time on June 28, 2016, by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter.

Yardangs not only reveal the strength and direction of historic winds, but also reveal something of the host rock itself. Close inspection by HiRISE shows an absence of boulders or rubble, especially along steep yardang cliffs and buttresses. The absence of rubble and the scale of the yardangs tells us that the host rock consists only of weakly cemented fine granules in tens of meters or more thick deposits. Such deposits could have come from extended settling of volcanic ash, atmospheric dust, or accumulations of wind deposited fine sands. After a time these deposits became cemented and cohesive, illustrated by the high standing relief and exposed cliffs.

https://www.nasa.gov/image-feature/wind-carved-rock-on-mars

[kanarkusmaximus]

Hmm, a jak sprawa marsjańskich żlebów? Czy pojawiły się nowe publikacje? Ostatnim razem była dyskusja, że żleby ("gullies") nie powstają wskutek oddziaływania wody. Czy jakieś kontr-publikację się pojawiły?

[Orionid]

Pod gruntem na Utopia Planitia zidentyfikowano więcej brudnego lodu wodnego, niż w innych częściach planety.

Scientists examined part of Mars' Utopia Planitia region, in the mid-northern latitudes, with the orbiter's ground-penetrating Shallow Radar (SHARAD) instrument. Analyses of data from more than 600 overhead passes with the onboard radar instrument reveal a deposit more extensive in area than the state of New Mexico. The deposit ranges in thickness from about 260 feet (80 meters) to about 560 feet (170 meters), with a composition that's 50 to 85 percent water ice, mixed with dust or larger rocky particles.

At the latitude of this deposit -- about halfway from the equator to the pole -- water ice cannot persist on the surface of Mars today. It sublimes into water vapor in the planet's thin, dry atmosphere. The Utopia deposit is shielded from the atmosphere by a soil covering estimated to be about 3 to 33 feet (1 to 10 meters) thick. (...)

The name Utopia Planitia translates loosely as the "plains of paradise." The newly surveyed ice deposit spans latitudes from 39 to 49 degrees within the plains. It represents less than one percent of all known water ice on Mars, but it more than doubles the volume of thick, buried ice sheets known in the northern plains. Ice deposits close to the surface are being considered as a resource for astronauts.

http://www.jpl.nasa.gov/news/news.php?feature=6680

[ekoplaneta]

Przypomina mi się, że coś podobnego znalazł kiedyś Mars Express, jeszcze około 2005 roku 

[Orionid]

Spękania wnętrza krateru spowodowane minionym lodem

Many impact craters on Mars were filled with ice in past climates. Sometimes this ice flows or slumps down the crater walls into the center and acquires concentric wrinkles as a result. This image shows an example of this.

There are other ways that scientists know the material in the crater is icy. Surface cracks that form polygonal shapes cover the material in the crater. They are easy to see in this spring-time image because seasonal frost hides inside the cracks, outlining them in bright white. These cracks form because ice within the ground expands and contracts a lot as it warms and cools.

http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA21215

[Orionid]

This image shows one of these exotic locales at the South Pole. The polar cap is made from carbon dioxide (dry ice), which does not occur naturally on the Earth. The circular pits are holes in this dry ice layer that expand by a few meters each Martian year.

New dry ice is constantly being added to this landscape by freezing directly out of the carbon dioxide atmosphere or falling as snow. Freezing out the atmosphere like this limits how cold the surface can get to the frost point at -130 degrees Celsius (-200 F). Nowhere on Mars can ever get any colder this, making this this coolest landscape on Earth and Mars combined.

http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA21216

[Orionid]

This image shows the floor of Suzhi Crater, an approximately 25-kilometer diameter impact crater located northeast of Hellas Planitia. The crater floor is mostly covered by dark-toned deposits; however some patches of the underlying light-toned bedrock are now exposed, like in this Context Camera image.

This enhanced-color infrared image shows a close up of the exposed bedrock on the floor of the crater. Here we can see the lighter-toned bedrock partially covered up by darker-toned bedrock and a few wind-blown bedforms. The lighter-toned bedrock appears to lie over yet another type of bedrock in our image, which appears to be yellowish and heavily fractured. What complex tale of Martian geologic and climate history might these rocks tell us if we were able to sample them in person? Perhaps, one day we'll know.

https://www.nasa.gov/image-feature/possible-layers-on-floor-of-suzhi-crater

[Orionid]

Proces z udziałem rozmrażającego się CO2 powoduje tworzenie kanałów w kształcie pajęczych nóg.

The type of terrain called spiders, or "araneiform" (from the Latin word for spiders), is characterized by multiple channels converging at a point, resembling a spider's long legs. Previous studies concluded that this ground texture results from extensive sheets of ice thawing bottom-side first as the ice is warmed by the ground below it. Thawed carbon dioxide gas builds up pressure, and the gas escapes through vents in the overlying sheet of remaining ice, pulling dust with it. This process carves the channels that resemble legs of a spider.

"The trapped carbon dioxide gas that carves the spiders in the ground also breaks through the thawing ice sheet," Schwamb said. "It lofts dust and dirt that local winds then sculpt into hundreds of thousands of dark fans that are observed from orbit. For the past decade, HiRISE has been monitoring this process on other parts of the south pole. The 20 new regions have been added to this seasonal monitoring campaign. Without the efforts of the public, we wouldn't be able to see how these regions evolve over the spring and summer compared with other regions." 

Some of the HiRISE observations guided by the volunteers' input confirmed "spider" terrain in areas not previously associated with carbon dioxide slab ice.

https://www.nasa.gov/feature/citizen-scientists-seek-south-pole-spiders-on-mars

[Orionid]

This composite image of Earth and its moon, as seen from Mars, combines the best Earth image with the best moon image from four sets of images acquired on Nov. 20, 2016, by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter.

Each was separately processed prior to combining them so that the moon is bright enough to see. The moon is much darker than Earth and would barely be visible at the same brightness scale as Earth. The combined view retains the correct sizes and positions of the two bodies relative to each other.

HiRISE takes images in three wavelength bands: infrared, red, and blue-green. These are displayed here as red, green, and blue, respectively. This is similar to Landsat images in which vegetation appears red. The reddish feature in the middle of the Earth image is Australia. Southeast Asia appears as the reddish area (due to vegetation) near the top; Antarctica is the bright blob at bottom-left. Other bright areas are clouds.

These images were acquired for calibration of HiRISE data, since the spectral reflectance of the Moon's near side is very well known. When the component images were taken, Mars was about 127 million miles (205 million kilometers) from Earth.

http://www.jpl.nasa.gov/spaceimages/details.php?id=pia21260

The High Resolution Imaging Science Experiment (HiRISE) camera would make a great backyard telescope for viewing Mars, and we can also use it at Mars to view other planets. This is an image of Earth and the moon, acquired on October 3, 2007, by the HiRISE camera on NASA's Mars Reconnaissance Orbiter.

At the time the image was taken, Earth was 142 million kilometers (88 million miles) from Mars.
http://photojournal.jpl.nasa.gov/catalog/PIA10244

EDIT:

MRO obserwuje Ziemię i Księżyca
PRZEZ KRZYSZTOF KANAWKA W DNIU 12 STYCZNIA 2017


Ziemia i Księżyc obserwowane przez instrument HiRISE / Credits - NASA/JPL-Caltech/Univ. of Arizona

Jak wygląda Ziemia z Marsa? Sonda Mars Reconnaissance Orbiter wykonała pod koniec listopada 2016 zdjęcia naszej planety i Księżyca przy użyciu teleskopu HiRISE.

Sonda Mars Reconnaissance Orbiter (MRO) krąży dookoła Czerwonej Planety od 10 marca 2006 roku. MRO został wyposażony w układ optyczny o aperturze 0,5 m. Ten instrument nosi nazwę High Resolution Imaging Science Experiment (HiRISE). Choć jest to pięć razy mniej od średnicy lustra słynnego kosmicznego teleskopu Hubble, HiRISE jest największym układem optycznym, jaki kiedykolwiek został wysłany poza bezpośrednie otoczenie Ziemi*. Rozdzielczość HiRISE sięga około 0,3 m z orbity o wysokości około 300 km.

Pod koniec listopada 2016 HiRISE wykonał zdjęcia Ziemi i Księżyca z odległości około 205 mln kilometrów. Zdjęcia wykonano w celu kalibracji HiRISE. Na początku stycznia 2017 NASA opublikowała przeprocesowane zdjęcie Ziemi i Księżyca, bardziej dla celów informacyjnych niż naukowych. W tym przypadku potrzebne było dostosowanie jasności Srebrnego Globu względem naszej planety, gdyż Księżyc jest znacznie ciemniejszy od Ziemi. W momencie wykonania zdjęć, z perspektywy Marsa nasz Księżyc był prawie dokładnie za Ziemią.

Na obrazie Ziemi można zobaczyć przede wszystkim kolor niebieski, pochodzący od oceanów oraz biały – od chmur i Antarktydy. Pomarańczowo-brązowy ląd widoczny na tym obrazie to Australia. W przypadku Księżyca można zobaczyć znacznie mniej szczegółów – w zasadzie jedynie różną jasność powierzchni Srebrnego Globu.

Oczywiście, głównym zadaniem MRO są obserwacje Marsa i jego księżyców. Rozdzielczość MRO pozwala na obserwacje bardzo drobnych szczegółów powierzchni Czerwonej Planety. Niedawno możliwości instrumentów MRO, w tym HiRISE okazały się być bardzo przydatne, podczas obserwacji regionu, na którym miał osiąść lądownik EDM Schiaparelli.

* W 2018 roku do punktu L2 układu Ziemia – Słońce zostanie wysłane kosmiczne obserwatorium JWST o średnicy lustra 6,5 metra.

(NASA)
Źródło: http://www.forum.kosmonauta.net/index.php?action=pm;sa=send;f=inbox;pmsg=4502;u=2031

[Orionid]

Pod koniec listopada 2016 HiRISE wykonał zdjęcia Ziemi i Księżyca z odległości około 205 mln kilometrów. Zdjęcia wykonano w celu kalibracji HiRISE. Na początku stycznia 2017 NASA opublikowała przeprocesowane zdjęcie Ziemi i Księżyca, bardziej dla celów informacyjnych niż naukowych. W tym przypadku potrzebne było dostosowanie jasności Srebrnego Globu względem naszej planety, gdyż Księżyc jest znacznie ciemniejszy od Ziemi. W momencie wykonania zdjęć, z perspektywy Marsa nasz Księżyc był prawie dokładnie za Ziemią.

Czy NASA ma jakąś specjalną stronę z takimi przeprocesowanymi zdjęciami ? Tzn. że są połączone różne obrazy w jeden, a potem widzimy takie dziwa jak fajnie oddalone obiekty . Czyli inaczej mówiąc, nie można było poczekać na czas, kiedy skala odległości będzie rzeczywista ?

[Orionid]

Stoki krateru Slope oczyszczone  przez staczające się kamienie i lawiny gruzu ukazują podpowierzchniowe warstwy.

Hues in a Crater Slope
Written by: Alfred McEwen  (2 January 2017)

Impact craters expose the subsurface materials on steep slopes. However, these slopes often experience rockfalls and debris avalanches that keep the surface clean of dust, revealing a variety of hues, like in this enhanced-color image, representing different rock types. The bright reddish material at the top of the crater rim is from a coating of the Martian dust.

The long streamers of material are from downslope movements. Also revealed in this slope are a variety of bedrock textures, with a mix of layered and jumbled deposits. This sample is typical of the Martian highlands, with lava flows and water-lain materials depositing layers, then broken up and jumbled by many impact events.

http://www.uahirise.org/ESP_021520_1550