Cloudy Mars



Image: NASA

Unbeknownst to many, Mars' thin atmosphere is rich in mysteries that scientists are slowly unraveling. In March 19, 2021 - just after sunset - NASA’s Curiosity Rover captured a strange cloud formation drifting over Aeolis Mons, a mountain located inside Gale crater.

The shimmering iridescent cloud formation is thought to occur during the coldest season, when the planet is the farthest from the Sun. The science team began observing the sky as early as January using the rover's Mastcam in the hopes of catching the transient atmospheric phenomenon early on. By late March of this year, they were rewarded with spectacular images of puffy clouds made out of frozen carbon dioxide peppered with ice crystals that scatter light from the setting Sun in a “mother of pearl" pattern.

Although scientists have yet to determine how these clouds form, the recent data obtained by the rover indicate a change in their composition, previously theorized to be mostly water ice, to more diverse elements such as carbon dioxide and nitrogen.