Did you know that liquid water once flowed across the landscape of Mars?
Mars (click to enlarge)

Geological features on Mars, including gullies, dried up river beds, and drainage basins, lead scientists to believe that liquid water once flowed on the planet's surface. Most scientists have interpreted these clues as indicating that Mars was both warmer and wetter in the past. Recently, however, evidence has accumulated that suggests that liquid water still reaches Mars's surface in today's cold and dry conditions. Read more.

Return to the Astronomy Workshop