Did Asteroid Impacts Incubate Mars' Ancient Oceans?

A bombardment of asteroids on a once-icy ancient Mars may have created vast oceans of liquid water, which persisted for 200 million years.

Published On 04/25/2016
11:32 AM EDT
The Opportunity rover (pictured in January 2016) may be examining an area that was covered in ocean a few billion years ago, new research suggests. | NASA/JPL-Caltech
Artist's impression of Comet Siding Spring making a close pass by Mars in October 2014. Mars has been hit by countless asteroids and comets in its history. | NASA's Goddard Space Flight Center Conceptual Image Lab