This well-preserved crater on Mars features evidence of mass wasting — reoccurring slope linea formation. Material is being eroded from the high-elevation crater lip, forming shifting gullies into the basin below.

Erosion in a Martian Crater

Two photographs from HiRISE on the Mars Reconnaissance Orbiter are blended together to produce this high-resolution digital terrain model (DTM). The rainbow colours indicate elevation, with high brown and red peaks running into dark blue and purple valleys. The plains outside the crater walls are rougher, with far more small impact craters speckling the lands.

Erosion in a Martian Crater

The well-preserved crater is located at -37.0°, 192.0° on Mars. The terrain model is made from extremely high-resolution stereo pairs, resulting in a map that so high resolution that each pixel represents one meter on the ground, with ground elevation differences measured in the tens of centimeters.

Building a digital elevation model is a time-consuming process, both computationally and in terms of human intervention. The basic steps are to prepare the images for input (or "ingestion") into the stereo software, triangulating the images, generating the DTM, editing any artifacts or anomalies, and finally orthorectifying the images to remove any optical distortions from tilt or perspective.

Image credit: NASA/JPL/University of Arizona/USGS. Check out a terrestrial rainbow landscape with this look at radar imagery over Ecuador.