Add Yahoo as a preferred source to see more of our stories on Google. This mosaic of images from the Mast Camera (Mastcam) ...

Scientists believe they found fresh proof of an ancient ocean on Mars in the form of a “bathtub ring” it left after it dried ...

The ancient ocean on Mars probably occupied a third of its surface.

A huge geological structure on Mars resembling a bathtub ring may be evidence of an ocean that once covered a third of the ...

By Will Dunham WASHINGTON, April 15 (Reuters) - There is a lot of evidence from orbiting satellites and surface rovers ...

Caltech researchers have identified geological features on Mars that could point to the existence of a long-dried ocean that ...

A new map reveals a blue Mars three billion years ago and strengthens the evidence of an ancient ocean that covered much of ...

Scientists have long known that Mars once had liquid water, but whether it formed only lakes and rivers or vast oceans has remained uncertain.

New research suggests an ancient ocean may have covered one-third of Mars, supported by elevation data, sediments, and rover findings.

Mars may have once possessed an ocean at least as large as Earth's Arctic Ocean, a new study suggests. Previous research suggested rivers and seas once existed on Mars, raising the question of whether ...

The red planet was half blue, according to space scientists. A research team using images from cameras on Mars-orbiting spacecraft say it was a "blue planet" around three billion years ago – with an ...

Since the first close-up observations of Mars, the ground of the Red Planet has revealed evidence of rivers, lakes, and more.