Mars' Hidden Past Reveals a Wetter, Warmer Planet The European Space Agency's Mars Express mission has been shedding light on the Red Planet's enigmatic past.
Its latest findings suggest that Mars was once home to a more hospitable environment. Shalbatana Vallis, a colossal valley near Mars' equator, is yielding dramatic clues about the planet's watery and volcanic history.
A Watery Past? The formation of Shalbatana Vallis around 3. 5 billion years ago suggests that vast amounts of groundwater burst onto the surface, carving deep channels across the Martian landscape.