Today's VIS image shows part of Arabia Terra. The different tones in the image indicate there is a difference between the dark and light surfaces. It could be due to differences in dust cover, or actual different layers of materials. Orbit Number: 87213 Latitude: 18.2372 Longitude: 335.439 Instrument: VIS Captured: 2021-08-12 10:16 https://photojournal.jpl.nasa.gov/catalog/PIA25205