The iridescent cloud reveals new clues about ice formation in the Martian atmosphere (no little green men, sorry).

The Sun sets differently on Mars. Part of that is due to its distance from the star (an average of 142 million miles versus Earth’s roughly 93 million miles), but it also has to do with the planet’s atmosphere. A great example of the effects can be seen in the Red Planet’s noctilucent clouds.

The phenomenon of twilight clouds was first observed on Mars in 1997 during NASA’s Pathfinder mission. However, it wasn’t until 2019 that the Curiosity Rover captured the firs