Posted on by Nancy Atkinson

Incredible 3-D View Inside a Martian Crater

A 3-d view of a well-preserved and unnamed impact crater on Mars, as seen by the HiRISE camera on the Mars Reconnaisancee Orbiter. Credit: NASA/JPL/University of Arizona. Click for high-resolution version.

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This is why I always keep a pair of 3-D glasses by my computer. This well-preserved crater on Mars may look like just your average, run-of-the-mill impact crater in 2-D, but in 3-D, the sharply raised rim, the deep, cavernous crater body, and especially the steep crater walls will have you grabbing your armchairs so you don’t fall in. The image is courtesy of the HiRISE camera team from the Mars Reconnaissance Orbiter. This unnamed crater is about 6 or 7 kilometers wide from rim to rim. HiRISE took the image on New Year’s Eve 2011.

HiRISE principal investigator Alfred McEwen says that the camera has imaged hundreds of well-preserved impact craters on Mars ranging from 1 meter to more than 100 kilometers wide. What can the scientists learn from craters?

“These targets are of great interest for multiple reasons,” he said. “First, we want to better understand impact cratering, a fundamental surface process. Second, such craters often contain good exposures of bedrock in the steep walls and, if the crater is large enough, in the central uplift. Just like terrestrial geologists are attracted to good bedrock outcrops like road cuts, planetary geologists are attracted to well-preserved craters.

“Third, the steep slopes often reveal active processes, such as formation of gullies, boulder falls, and slope streaks that could form in a variety of ways. Some of these active processes could be related to water, since the crater may expose lenses of ice or salty water, or create deep shadows that trap volatiles, or expose salts that can extract water from the air.”

Plus, they are just plain wonderful to behold, especially in the resolution the HiRISE can obtain.

A non-3-D version of the same image. Credit: NASA/JPL/University of Arizona

Source: HiRISE

Posted on by Nancy Atkinson

Scientists Still Searching for the Beagle 2 Crash Site on Mars

An image from the HiRISE camera of the Isidis basin region where the Beagle 2 lander was supposed to touch down. Credit: NASA/JPL/University of Arizona

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Since its disappearance in December 2003, scientists and citizen scientists alike have continued the search for Europe’s Beagle 2 lander which likely crashed on Mars. Its disappearance is a mystery and if the spacecraft could be located, it might be possible to discover what went wrong.

The Mars Reconnaissance Orbiter’s powerful HiRISE camera has been regularly taking high-resolution images of the Isidis basin region where the Beagle 2 lander was supposed to touch down.

“Nothing resembling the Beagle lander has been seen in any of the HiRISE images, although we aren’t sure that they’ve been thoroughly searched,” said HiRISE Principal Investigator Alfred McEwen, writing on the HiRISE website.

So, join in the search and take a look!

Above is the 12th such image taken by HiRISE.

McEwen said the easiest thing to spot would be the bright parachute — if it actually deployed. Remember how HiRISE was able to find the parachutes at the MER landing sites, and even capture the Phoenix lander descending on its parachute? The Beagle 2’s parachute would be a good clue to search for.

(As we reported earlier, the HiRISE team will attempt to image the Mars Science Laboratory during its descent to Mars’ surface in August, as it did for Phoenix.)

Dust should not be a problem as far as hiding the lander or parachutes, McEwen said. “Dust deposition over the past eight years probably would not disguise the bright feature over equatorial regions of Mars,” he said noting that the parachutes are still easy to spot at the MER and Pathfinder landing sites. “At high latitudes the brightness patterns are reset each winter by the seasonal deposits of carbon-dioxide and dust, as seen at the Phoenix landing site.”

All contact with Beagle 2 was lost after its separation from the Mars Express spacecraft, just six days before atmospheric entry. McEwen said the lack of telemetry on its way to the surface means there is little information about where the spacecraft may have landed on the surface, but searching in the region where it was expected to land is a good place to start.

You can download high-resolution version of this images here.

For an idea of what the Beagle 2 hardware might look like, see this web page.

Posted on by Tammy Plotner

Martian Clay A Vessel For Water?

Light-Toned Deposits: This image reveals exposed layers in Noctis Labyrinthus which may contain signatures of iron bearing sulfates and phyllosilcate (clay) minerals. Image Credit: NASA/JPL-Caltech/University of Arizona

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Although it might seem like a fictitious nomenclature, smectite is a real substance and it’s been found on Mars. It’s a clay mineral that, like a sponge, expands and contracts as it takes on liquid water. With magnesium, iron, aluminum and silica in their content, smectites are morphed into being when silicates are exposed to non-acid water. Now Mars has yielded up two such deposits that further indicate the presence of a once wetter world.

“We discovered locations at Noctis Labyrinthus that show many kinds of minerals that formed by water activity,” said Catherine Weitz, lead author and senior scientist at the Planetary Science Institute. “The clays we found, called iron/magnesium (Fe/Mg)-smectites, are much younger at Noctis Labyrinthus relative to those found in the ancient rocks on Mars, which indicates a different water environment in these depressions relative to what was happening elsewhere on Mars.”

Thanks to high-resolution images from the High Resolution Imaging Science Experiment (HiRISE) camera and hyperspectral data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) on the Mars Reconnaissance Orbiter (MRO) spacecraft, combined with Digital Terrain Models (DTMs), Weitz and her team observed about 300 meters of escarpment restricted to two 30 to 40 kilometer troughs located at the western edge of the Vallis Marineris canyon. By studying the “geological layers” the team was able to map hydrated minerals and better understand how the water chemistry evolved.

“These clays formed from persistent water in neutral to basic conditions around 2 to 3 billion years ago, indicating these two troughs are unique and could have been a more habitable region on Mars at a time when drier conditions dominated the surface,” said co-author and CRISM team member Janice Bishop from the SETI Institute and NASA AMES Research Center.

The huge troughs reveal a rich geological chronicle of events. Like reading a book, each layer is a chapter in Martian water history. As they would fill, they would take on a chemical signature of that era. Then the troughs would erode and nearby volcanism added its own particular brands. Again, they would fill and chemicals would mix. Even the pH levels of the water adds its own fingerprint to the smectite equation. While it isn’t a unique find, what sets this area apart is that things appear to have happened in a reverse order as opposed to what happened globally across Mars. As exciting as these new finds are, for now studies will have to remain photographic.

“These troughs would be fantastic places to send a rover, but unfortunately the rugged terrain makes it unsafe both for landing and for driving,” Weitz said.

Original Story Source: Planetary Science Institute Press Release.