Why is Mars barren and uninhabitable, while life has always thrived here on our relatively similar planet Earth?

The thick, mineral-rich layers of clay found on Mars suggest that the Red Planet harbored potentially life-hosting ...

Primitive life forms thrived on Mars around the same time prehistoric life was developing in Earth's oceans -- but the Red Planet's denizens doomed themselves, a new study suggests.

Mars is not an easy place to live. The Red Planet is essentially one giant desert with a minimal atmosphere, low temperatures and no liquid water at its surface. But the biggest barrier to life on ...

Data fed into computer models shows that microscopic life forms may once have thrived there -- and may have left behind evidence of their existence. Eric Mack has been a CNET contributor since ...

We may have already encountered Martian life about 30 years ago and accidentally killed it, according to a new analysis of NASA's Viking mission to Mars presented Sunday at a major astronomy ...

CAPE CANAVERAL, Fla. (AP) — Ancient Mars may have had an environment capable of harboring an underground world teeming with microscopic organisms, French scientists reported Monday. But if they ...

A rock on Mars spilled a surprising yellow treasure after Curiosity accidentally cracked through its unremarkable exterior.

The idea of Mars being host to extraterrestrial life, either currently or long ago in the past, has beguiled scientists for centuries. The discovery of frozen water on the Red Planet gave ...

A search for life on Mars— even in the form of microorganisms lying beneath its polar caps or in subterranean hot springs warmed by vents from the Martian core—fuels this quest.