Mars exploration has been guided by the search for water. The more complex quest by Mars Science Laboratory for habitable environments should illuminate the Martian environmental history, and ...

Some scientists aren't so sure. Scientists are confident Mars was once abundant with water, as seen in massive flood-carved channels, ancient river valleys, and minerals that form only in liquid ...

Utopia Planitia dates to the Hesperian Period, or 3.7 billion to 3 billion years ago, and it lacks abundant evidence for standing water, unlike more ancient regions of Mars, said Aaron Cavosie ...