Until then, telescopic images of Mars – namely enigmatic dark patches on its surface – triggered the belief that it was home to an alien civilization. But Mariner 4 revealed a barren planet ...

In the 1970s, images from the NASA Mariner 9 orbiter revealed water-sculpted surfaces on Mars. This settled the once-controversial question of whether water ever rippled over the red planet.

Since the Mars Express entered orbit around Mars on Christmas Day 2003, the orbiter has been snapping images of the Martian surface from an altitude of around 186 miles (300 kilometers), the ...

In the 1970s, images from the NASA Mariner 9 orbiter revealed water-sculpted surfaces on Mars. This settled the once-controversial question of whether water ever rippled over the red planet.