NASA's Curiosity rover has captured images of rainbow-colored noctilucent clouds in Mars' atmosphere. Made of dry ice, these aren't like Earth's clouds.

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

The clouds, composed of carbon dioxide ice crystals, glow in shades of red, green, and pearlescent hues in the martian twilight.

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.