New evidence of ancient rivers suggests Mars may have been a "blue planet," thanks to an ocean spanning its entire northern ...

Spacecraft orbiting the Red Planet have helped researchers map out an ancient coastline that surrounded a large ocean billions of years ago ...

At half the size of Earth and one-tenth its mass, Mars is a featherweight as far as planets go. Yet new research reveals the ...

Mars had an Arctic-sized ocean, and scientists are only now beginning to see the outline of it. For a long time, the planet ...

This doesn’t mean Mars causes ice ages on its own. Orbital cycles are only part of the picture. Earth’s oceans, atmosphere, ...