NASA Mars Curiosity Rover: 2% Water found in surface soil

Future Mars explorers may be able to get all the water they need out of the red dirt beneath their boots, a new study suggests.

NASA's Mars rover Curiosity has found that surface soil on the Red Planet contains about 2 percent water by weight.

That means astronaut pioneers could extract roughly 2 pints (1 liter) of water out of every cubic foot (0.03 cubic meters) of Martian dirt they dig up, said study lead author Laurie Leshin, of Rensselaer Polytechnic Institute in Troy, N.Y.

"For me, that was a big 'wow' moment," Leshin told reporters. "I was really happy when we saw that there's easily accessible water here in the dirt beneath your feet. And it's probably true anywhere you go on Mars."

The new study is one of five papers published in the journal Science today (Sept. 26) that report what researchers have learned about Martian surface materials from the work did during its first 100 days on the Red Planet.



Soaking up atmospheric water
Curiosity touched down inside Mars' huge Gale Crater in August 2012, kicking off a planned two-year surface mission to determine if the Red Planet could ever have supported microbial life.

It achieved that goal in March, when it found that a spot near its landing site called Yellowknife Bay was indeed habitable billions of years ago.

Laurie Leshin

But Curiosity did quite a bit of science work before getting to Yellowknife Bay. Leshin and her colleagues looked at the results of Curiosity's first extensive Mars soil analyses, which the 1-ton rover performed on dirt that it scooped up at a sandy site called Rocknest in November 2012.

Using its Sample Analysis at Mars instrument (SAM), Curiosity heated this dirt to a temperature of 1,535 degrees Fahrenheit (835 degrees Celsius), and then identified the gases that boiled off.

SAM saw significant amounts of carbon dioxide, oxygen and sulfur compounds — and lots of water on Mars.

Sample Analysis at Mars instrument (SAM)

SAM also determined that the soil water is rich in deuterium, a "heavy" isotope of hydrogen that contains one neutron and one proton (as opposed to "normal" hydrogen atoms, which have no neutrons).

The water in Mars' thin air sports a similar deuterium ratio, Leshin said.

"That tells us that the dirt is acting like a bit of a sponge and absorbing water from the atmosphere," she said.