A most breath-taking image of MARS
• Crater Wall Straddling Two Terrain Units
09/07/2018
In this oblique view by the Mars Orbiter this impact crater located in northern Sinus Meridiani has formed along the boundary of two different terrain units. The western part of the crater has formed along a unit consisting of wind-blown basaltic materials that overlie light-toned units exposed in the crater wall.
To the east is a shallow circular depression several kilometers across that consists of multiple layers of light-toned deposits that have been eroding away. These deposits are dark in THEMIS night-time infrared and bright in day-time infrared images, suggesting that they are relatively fine grained and largely devoid of rocky materials.
Dark, fine-grained basaltic wind-blown material partially mantles these units and forms dunes throughout the region. Along the eastern rim region, the impact crater is eroding back into the terrain, forming scalloped inlets in the crater rim and re-exposing the multiple layers of light-toned deposits. Terracing is common along the eastern slope of the crater.
The erosion of the top units appear to be more even and at a faster rate than the underlying deposits. Dark wind-blown basaltic dunes line the floor of the crater. Some possible explanations for the origin of these light-toned deposits are that they are altered volcanic ash or ancient lake deposits.
The shadows from the cliffs really gives it depth but in all those shots it's hard to get a sense of scale. No recognisable features or trees. Could be a couple 100m or a couple of km high.