THEMIS Image of the Day, August 1, 2019. This VIS image is located where the southeastern flank of Ascraeus Mons meets the surrounding volcanic plains. Ascraeus Mons is the northernmost of the three large Tharsis volcanoes.
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Sols 2482-83, July 30, 2019, update by MSL scientist Mariah Baker: The rover is currently located in the southern part of the “Visionarium,” where we are set to start our next drill campaign, and we can’t help but take in the scenery! Perched on top of a small escarpment, we have arguably one of the best backdrops we have ever had during a drill campaign. The stunning panoramic views of Mount Sharp and surrounding terrains (like those seen in the Navcam image above) could truly take one’s breath away – if the lack of oxygen wasn’t enough!
Today marked drill Sol 1, which meant the team was focused on locating and prioritizing drillable rocks in our workspace. The target “Glen Etive 1″ was selected as the primary drill option; ChemCam, MAHLI, and APXS measurements on Glen Etive 1 will provide information on the geologic and chemical properties of this rock before we start to drill. ChemCam will also target another spot on the same rock layer (“Glen Etive 2″) as well as a target on another outcrop nearby (“Ninian”). We also included… [More at link]
Possible jarosite on a plateau in Nili Fossae. Recent analyses of CRISM data have discovered jarosite in this portion of the trough wall, possibly within a previously identified aluminum clay unit. Jarosite is a sulfate mineral also detected by the Spirit and Opportunity rovers.
HiRISE Picture of the Day archive. [More at links]
THEMIS Image of the Day, July 31, 2019. Today’s VIS image shows part a section of a mega gully. Located on the plains of Sinai Planum, it is just one of a number of huge channels that line the cliff face of Ius Chasma.
The linear sides of the channel indicate that the formation of these features included tectonic activity. Ius Chasma is on the western end of Valles Marineris.
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Small craters in Promethei Terra. The target area is for the theoretical landing of a rover, in a flat area close by. The craters in the target area are important because they are a potential source of rock samples that would be gathered by the rover, ejected from said craters.
HiRISE Picture of the Day archive. [More at links]
Sol 2480, July 29, 2019. From atop the Southern Outcrop, five Navcam frames profile the exposed rock in front of Curiosity, as well as the terrain it has crossed to get here — note the two wheel tracks as they zigzag in the middle distance and at right. (The area under consideration for drilling lies roughly in the center of the exposure.)
Farther away a dark feature (Vera Rubin Ridge) winds across the ground, while more distant still the floor of Gale Crater stretches away until it reaches the inside face of the crater’s northern rim, which forms the horizon. Click the image to enlarge it.
THEMIS Image of the Day, July 30, 2019. This fracture system is called Elysium Chasma. Located west of Elysium Mons, it is just one of many large fractures in the Elysium volcanic complex.
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Sol 2481, July 29, 2019, update by MSL scientist Vivian Sun: After a successful ascent to the top of the southern outcrop in the “Visionarium,” we are now searching for our next drill site. There were no bedrock exposures available for contact science activities in our immediate workspace, so our first order of business today was to identify a drill site area that we will drive to in today’s plan.
There are a number of factors we considered when selecting this drill site. We looked for bedrock that looked “in-place,” meaning bedrock that likely has not been moved since it formed. While there can be “out-of-place” rocks (or “float” rocks) that are interesting, in-place bedrock can be more stable for drilling and its geologic context is simpler to interpret. We also prioritized larger bedrock exposures, as we need room to drill, discard, and analyze the sample. The size of the bedrock slab is even more important than usual at this location because we may consider drilling a second time and delivering sample for a possible SAM wet chemistry experiment. Lastly, we considered other practical constraints, like finding an area that gives us a good parking position and a level surface to drill on. Considering all of these factors, we identified several candidate sites and finally decided to drive to… [More at link]
[Editor’s note: From a paper by Christine Simurda and two co-authors recently published in the Journal of Geophysical Research.]
The Unusual Thermophysical and Surface Properties of the Daedalia Planum Lava Flows
• Unusual thermophysical variations are present on lava flows in Daedalia Planum that are not easily explained by observed thermal inertia
• A multi‐instrument, multispectral approach is used to identify the potential subpixel distribution of lava outcrops, sand, and dust
• Rough surfaces with a low day and high night temperature response contain the greatest percentage of exposed lava outcrops in the flow field
Daedalia Planum contains some of the youngest and most abundant volcanic activity on Mars. The lava flows exposed here were considered too dusty for previous thermal infrared studies, but our analysis suggests that the dust is not uniform and these surfaces contain significant proportions of lava outcrops rising above low‐lying regions of sand with a discontinuous dust cover.
The presence of different areal distributions of dust, sand, and lava outcrops on these flows is further supported by the unusual temperature behavior between flows as well as other studies showing that these flows have the roughest surfaces on Mars. Visible data are used to investigate the flow surface morphology and potential degree of dust cover. Thermal data combined with a thermophysical classification are used to evaluate the temperature response between.
These temperature variations are due to different distributions of lava outcrops, sand infill, and dust mantling. Most lava flows with a rough surface display a temperature response suggesting the presence of a larger percentage of lava outcrops versus sand and dust. These surfaces, identified as having minimal dust or more exposed outcrop, represent promising new targets for future compositional analysis. [More at link]
