Most debris on crater walls slides straight downhill. In this HiRISE image we see examples of boulders that have bounced downhill, not necessarily vertically. A prominent example looks like a dotted line from the top of the crater wall where the boulder took off to the crater floor where it finally came to rest.
HiRISE Picture of the Day archive. [More at links]
THEMIS Image of the Day, April 8, 2019. Today’s false-color VIS image is located in Aram Chaos. Aram Chaos was initially formed by a large impact. Over time the crater interior was modified by several different processes, including liquid water.
Located near Ares Vallis, a narrow channel links the Aram Chaos crater with Ares Vallis indicating a substantial amount of water was located in the crater. Chaos forms from erosion of the surface into mesa features. With time the valleys expand creating the jumble of hills seen in the image.
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.
Sol 2368, April 5, 2019. A partial front Hazcam image shows the rover’s drill poised to bite into the target dubbed Aberlady. Click the image to enlarge it.
In this MAVEN outreach webinar from March 27, 2019, Dr. Gina DiBraccio from NASA’s Goddard Space Flight Center describes what makes the Martian magnetic environment so different from other planets, and how processes in its magnetotail may contribute to atmospheric escape to space… [More at link]
This image is part of a campaign to image potential impact craters in the south polar layered deposits (ice cap). This feature looks like a strong candidate for an impact crater because it is very circular are still has a raised rim.
The sizes and densities of impact craters provide an estimate for the age of the landscape, which in turn provides a minimum age for the icy layers.
Sol 2368, April 5, 2019, update by MSL scientist Mark Salvatore: Today marks the conclusion of the MSL Science Team Meeting currently taking place at Goddard Space Flight Center in Greenbelt, MD. These meetings are where scientists and engineers can come together to discuss the ongoing activities associated with the Curiosity rover. They’re always productive opportunities to discuss strategies for analyzing previously collected data as well as strategies for investigating the terrain ahead of the rover.
After significant discussion among the science team as well as analysis of the compositional data that came down overnight from both the APXS and ChemCam instruments, the team has decided to proceed with drilling the Aberlady target. The additional compositional analyses confirmed that the composition of this target looks comparable to other targets within the clay-bearing unit. So, with the team coming to this… [More at link]
THEMIS Image of the Day, April 5, 2019. This false-color VIS image is located in the center of Syrtis Major Planum. At the top of the image is Nili Patera, a volcanic summit.
The sand dunes located near Nili Patera are visible on the left side of the image. The bottom of the image is just west of Meroe Patera. Dunes located between Nili and Meroe are visible towards the bottom of the image.
Winds in the region have created the dunes, but also many windstreaks on the downward side of craters in the image. Wind streaks indicate the direction of the wind. In this region the winds are blowing from east to west.
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.
When NASA’s Curiosity Mars rover landed in 2012, it brought along eclipse glasses. The solar filters on its Mast Camera (Mastcam) allow it to stare directly at the Sun. Over the past few weeks, Curiosity has been putting them to good use by sending back some spectacular imagery of solar eclipses caused by Phobos and Deimos, Mars’ two moons.
Phobos, which is about 7 miles (11.5 kilometers) across, was imaged on March 26, 2019 (the 2,359th sol, or Martian day, of Curiosity’s mission); Deimos, which is about 1.5 miles (2.3 kilometers) across, was photographed on March 17, 2019 (Sol 2350)….
Solar eclipses have been seen many times by Curiosity and other rovers in the past. Besides being cool – who doesn’t love an eclipse? – these events also serve a scientific purpose, helping researchers fine-tune their understanding of each moon’s orbit around Mars.
Before the Spirit and Opportunity rovers landed in 2004, there was much higher uncertainty in the orbit of each moon, said Mark Lemmon of Texas A&M University, College Station, a co-investigator with Curiosity’s Mastcam. The first time one of the rovers tried to image Deimos eclipsing the Sun, they found the moon was 25 miles (40 kilometers) away from where they expected.
“More observations over time help pin down the details of each orbit,” Lemmon said. “Those orbits change all the time in response to the gravitational pull of Mars, Jupiter or even each Martian moon pulling on the other.” [More at link]
Sol 2367, April 4, 2019. The rover’s ChemCam laser stitched a row of pits across Aberlady (above).
At right, the front Hazcam showed the scene with Curiosity’s instrument arm close to the target. (Compare this view with that here.)
Click either image to enlarge it.
