Scientists looking at potential colony locations on Mars may not need to do much searching after an unmanned probe found an enormous water source on the red planet.
NASA's Mars Reconnaissance Orbiter completed more than 600 overhead passes of a region known as Utopia Planitia, "planes of paradise," using its Shallow Radar to locate the abundant water, the space agency announced.
Previous probes haven't found water on the surface of Mars because it "sublimes into water vapor in the planet's thin, dry atmosphere," NASA said.
But scientists have known for some time that the planet is home to sub-surface ice, and the newly-discovered water ice deposit is protected by a blanket of soil that ranges from only 3 feet thick to 33 feet thick.
There's a lot of it under that shield of dirt -- enough to match the water content of Lake Superior, covering an area larger than New Mexico, scientists say.
"This deposit probably formed as snowfall accumulating into an ice sheet mixed with dust during a period in Mars history when the planet's axis was more tilted than it is today," said Cassie Stuurman of the Institute for Geophysics at the University of Texas and the lead author of a report in the journal Geophysical Research Letters detailing the find.
Throughout history, civilizations large and small have been founded on the banks of rivers or in natural inlets, and future colonization efforts on Mars are expected to follow the same pattern. From Mesopotamia and Egypt to the Indus Valley and pre-dynastic China, cities founded near major waterways used irrigation systems to cultivate food crops.
Where there's water, there's life.
The massive water deposit at Utopia Planitia is easier for a fledgling colony to reach, the University of Texas' Jack Holt said. Unlike other large water ice deposits on Mars, which tend to be clustered near the planet's poles, the Utopia Planitia deposit ranges from the equator northward, a much more viable location for settlements.
"This deposit is probably more accessible than most water ice on Mars, because it is at a relatively low latitude and it lies in a flat, smooth area where landing a spacecraft would be easier than at some of the other areas with buried ice," said Holt, co-author of the Utopia paper.
While the discovery has futurists and proponents of space colonization buzzing, it's also an important clue to discovering more about the planet's history, Joe Levy of the University of Texas and co-author of the report, said.
"The ice deposits in Utopia Planitia aren’t just an exploration resource, they’re also one of the most accessible climate change records on Mars," said Levy. "We don’t understand fully why ice has built up in some areas of the Martian surface and not in others. Sampling and using this ice with a future mission could help keep astronauts alive, while also helping them unlock the secrets of Martian ice ages.”