A strange rock on Mars is raising new questions about the possibility of ancient microbial life on the Red Planet. According ...

Perhaps the most controversial of the possible signs of water on Mars are recurring slope lineae, which are dark streaks that ...

If true, this further supports the hypothesis that an ocean once covered a substantial portion of the northern pole of Mars. A body of water big enough to generate waves and tides also raises the ...

The recent study, however, challenged this idea by conducting new analyses of various spacecraft observations as well as running ... when water was still present on the surface, Mars rusted ...