NASA's Curiosity rover taking a picture of itself on Mars. (Photo/NASA/JPL) At the surface, Mars is a desolate, barren world with a rocky landscape, massive dust storms and extreme temperature swings.

Colorful noctilucent clouds were spotted in the Martian sky on Jan. 17 as NASA's Curiosity rover pointed one of its cameras up during twilight. These types of clouds form high in the atmosphere and ...