Nasa Mars Global Surveyor: Was there an ocean on the Red Planet?

The scientists used data gathered from Nasa’s Mars Global Surveyor.

Planetary scientist Michael Lamb says “interpreting ancient landforms is not easy”, their study shows “telltale signs of a coastal shelf”.

There are also areas on the Red Planet where rivers may have flowed into a larger body of water.

Which means that Mars may once have looked much more like Earth than it does now.