THEMIS Image of the Day, April 22, 2019. Today’s VIS image shows the floor of Matara Crater. A large sand sheet with surface dune forms dominates the floor of this crater located in Noachis Terra. The dunes’ dark tone indicates a lack of dust, which is light in tone. Thus the dune sands are probably active and moving under the wind.
Explore more THEMIS Images of the Day by geological subject.
Sols 2383-2385, April 19, 2019, update by MSL scientist Abigail Fraeman: Yestersol’s drill pre-load test was successful, so today we are go for a drill attempt at “Kilmarie”! The front hazcam image from yesterday’s test (shown above) is a helpful visual for understanding how close our new drill location will be to the last drill at “Aberlady.” In this image, you can see Curiosity resting the point of the drill on the future Kilmarie drill target along with the old Aberlady drill hole, a little to the left of the arm. It’s been a while since we’ve drilled two locations so close together! Avid readers of this blog will recall we decided to drill again in this area because we saw some irregularities during drilling Aberlady. Specifically, we weren’t sure we’d collected enough drill material for both CheMin and SAM analyses at the Aberlady location, so we’re hoping we can be more confident in the amount of sample we collect at Kilmarie… [More at link]
[Editor’s note: From a paper by Jonathan Bapst and three co-authors recently published in the Journal of Geophysical Research.]
Thermophysical Properties of the North Polar Residual Cap using MGS TES
• We identify residual water ice with elevated surface porosity (>40%) that is densified at depths <0.5 m, consistent with recent accumulation.
• Denser, vertically-homogeneous ice is detected at the residual cap edge, consistent with ablation and exhumation of older, densified ice.
The polar regions of Mars host kilometers-thick stacks of water ice that have been built up over millions of years. At the north pole today, the top of this ice deposit is interacting with the martian atmosphere. Whether or not ice at the surface is fluffy (like snow) or dense (like an ice slab) can provide useful information about the polar ice cap and recent climate.
Multiple years of surface temperature measurements have been acquired by instruments aboard spacecraft in orbit around Mars. By comparing these values with temperature simulations, we can narrow down the type of ice near the surface.
Our results show that the type of ice varies across the polar cap. Some regions appear to be a snow-like surface where the polar cap may be growing. Other regions, most notably along the edge of the polar cap, show denser ice that is likely older. The nature of the ice tells us about the current climate and how these kilometer-thick ice deposits form. [More at link]
Sol 2382, April 19, 2019, update by MSL scientist Susanne Schwenzer: Some days just give me goose bumps. First, looking at yesterday’s plan I realized that we did something really unusual overnight: Wrap up the drill activity on one site and start the drill activities on the next in the same sol. As reported yesterday, we said Good-bye to “Aberlady,” and we turned the rover to “Kilmarie,” our next drill target. The two targets are just 80 centimetres away from each other.
But that was not the only thing that made the day special. On some days we start planning just before the MRO (Mars Reconnaissance Orbiter) data downlink is due to deliver the data that we need for planning. Today was such a day. Seeing the data arrive, displaying them the moment they show up, and discussing what we see immediately after the data reached us, is one of the most exciting moments of such a… [More at link]
[Editor’s note: From a paper by Solmaz Adeli and five co-authors recently published in the Journal of Geophysical Research.]
Geomorphological evidence of localized stagnant ice deposits in Terra Cimmeria, Mars
• Small debris‐covered stagnant ice deposits (termed valley fill deposits or VFD) are located inside a valleys system in Terra Cimmeria, Mars.
• Morphological properties (convex‐upward morphology, crevasses, and sublimation pits) suggest a current degradational stage of VFD evolution.
• The location of VFD within the ejecta blanket of Middle Amazonian Tarq crater points to impact into shallow ice as likely formation process.
In the last two decades with the increase of high resolution imagery data, more studies report the presence of ice deposits covered by dust and debris on the Martian surface, in both mid‐latitudes. These deposits must have been formed under different atmospheric conditions, since water ice is not stable in the current surface environment.
One of the generally accepted hypotheses for their formation is precipitation induced by variations of Mars’ axial tilt known as obliquity. During high obliquity phases, ice would have sublimated from the poles and re‐deposited in the mid‐latitudes.
Here, we report the presence of small‐scale ice deposits, located on the floor of a valley system in Terra Cimmeria. Although it is clear that these deposits were formed in different climatic conditions, their formation seems to be related to an impact into a shallow subsurface ice layer, redistributing a mixture of ejected material and ice across the region around the impact site.
This study shows the importance of local geological processes, e.g. impact cratering, in investigations of water ice distribution on Mars. Near‐surface ice reservoirs are of high importance in the search for life, and for future human exploration on Mars. [More at link]
HiRISE has often imaged inside Kaiser Crater to monitor active sand dunes and gullies. Surrounding these dunes, we often find clean bedrock exposures, because the actively moving sand clears off the dust.
Kaiser Crater is 207 kilometers wide and was named after Frederik Kaiser, a Dutch astronomer (1808—1872).
THEMIS Image of the Day, April 19, 2019. Today’s false-color image shows part of Bonestell Crater. This is a relatively young crater located in Acidalia Planitia.
Dust blown into the crater and the downslope movement of fine materials from the rim are slowly modifying the crater features. This material is responsible for the sand dunes visible at the bottom of the image. Dark blue tones in this false color combination typically indicate basaltic materials.
The THEMIS VIS camera contains 5 filters. The data from different filters can be combined in multiple ways to create a false color image. These false color images may reveal subtle variations of the surface not easily identified in a single band image.
Explore more THEMIS Images of the Day by geological subject.
Pits and depressions to the east of Juventae Chasma. Juventae Chasma is a large box canyon, located north of Valles Marineris in the Coprates quadrangle and cuts more than 5 kilometers into the plains of Lunae Planum.
HiRISE Picture of the Day archive. [More at links]
For the past few months, the clean room floor in High Bay 1 at NASA’s Jet Propulsion Laboratory in Pasadena, California, has been covered in parts, components and test equipment for the Mars 2020 spacecraft, scheduled for launch toward the Red Planet in July of 2020. But over the past few weeks, some of these components – the spacecraft-rocket-laden landing system and even the stand-in for the rover (christened “surrogate-rover”) – have seemingly disappeared.
In reality, they are still there, tucked neatly into the entry capsule, as they will be when it’s time for launch. The procedure is known as vehicle stacking and involves a hyper-detailed plan for what goes where and when.
“One of our main jobs is to make sure the rover and all the hardware that is required to get the rover from here on Earth to the surface of Mars fits inside the payload fairing of an Atlas V rocket, which gives us about 15 feet [5 meters] of width to work with,” said David Gruel, assembly, test and launch operations (ATLO) manager for Mars 2020 at JPL.
The first step is to place the rocket-powered descent stage on top of the surrogate rover (the real rover is being integrated and tested in tandem with the spacecraft stack). Then, when all the holes line up and everything is attached, checked and re-checked again, the back shell is lowered over them via gantry crane… [More at link]
