Varied Types of Rock in a Crater in Eos Chasma

This image shows a crater on the floor of Eos Chasma, part of the Valles Marineris canyon system. Craters on Mars are useful for geologists because they provide cross-sections into the subsurface. The south wall of this crater shows evidence of several different types of rock, with diverse colors. In the black and white parts of the image, it appears that there are two types of rock: one relatively light and one dark. However, in the 1.1 kilometer-wide color swath we can see that the dark rocks are more complicated, as some have a greenish tint and others are purple. Note that these are not the colors your eyes would see if you were there! In enhanced color, the HiRISE near-infrared data appears as red, the red is shown as green, and the blue-green data is shown as blue, allowing us to see more information at once. https://photojournal.jpl.nasa.gov/catalog/PIA25182