File:ESP 031221 1315-Mars-CopernicusCrater-OlivineDuneTerrain-20190831.jpg

English: Raindrops of Sand in Copernicus Crater

https://www.uahirise.org/hipod/ESP_031221_1315

https://www.sciencealert.com/these-images-showcase-mars-at-its-most-gloriously-alien

The dark features here look like raindrops, but are actually sand dunes. This spot was targeted by CRISM because the dunes are rich in the mineral olivine.

Olivine-rich dunes are very rare on Earth, as olivine rapidly weathers to clays in a wet environment. There is also olivine-rich bedrock in the central peaks of Copernicus Crater on the Moon.

There is only a handful of very important scientists, like Nicolaus Copernicus (1473-1543) who have craters named after them on both Mars and the Moon.