Liquid water may still flow on Mars, but that doesn’t mean it’s easy to spot.
The search for water on the Red Planet has taken more than 15 years to turn up definitive signs that liquid flows on the surface today. In the past, however, rivers and oceans may have covered the land. Observations of the Red Planet indicate that rivers and oceans may have been prominent features in its early history.
Billions of years ago, Mars was a warm and wet world that could have supported microbial life in some regions. Vast deposits of water appear to be trapped within the ice caps at the north and south poles of the planet. Frozen water also lies beneath the surface.
Scientists discovered a slab of ice as large as California and Texas combined in the region between the equator and north pole of the Red Planet.
The European Space Agency’s Mars Express spacecraft captured images of sheets of ice in the cooler, shadowed bottoms of craters, which suggests that liquid water can pool under appropriate conditions.
The flatter northern plains of Mars may once have hosted an ocean or possibly, as the planet cycled through dry periods, two.
The more recent body of water would likely have only been temporary, seeping into the ground, evaporating, or freezing in less than a million years, scientists say.
Curiosity determined that Mars could indeed have supported microbial life in the ancient past, and the next NASA rover — a car-size robot based heavily on Curiosity’s basic design — will blast off in 2020 to look for evidence of past Red Planet life. Read more.