Evidence of ancient ponding has been uncovered at scales ranging from a few kilometers to possibly that of the Arctic ocean. Whether life existed on Mars is still unknown ... activity and impact ...

Researchers have found new evidence for a massive subsurface ocean on Mars, again raising the possibility of microbial life lurking deep below the Martian surface. As detailed in a paper in the ...

A hypothetical picture of Mars 3.6 billion years ago, when an ocean may have covered nearly half the planet. The blue areas show the depth of the ocean filled to the shoreline level of the ancient ...

has found new geological evidence suggesting that Mars might have once hosted a vast ocean. The study, published in Nature, strengthens the theory that an ocean may have covered nearly a third of ...