How's the water on Mars? Curiosity rover finds out.

NASA's Curiosity Mars rover has detected water locked inside a rock, shedding light on what the Red Planet's surface water was like billions of years ago.

NASA/JPL-Caltech/MSSS
The hole drilled into this rock target, called "Cumberland," was made by NASA's Mars rover Curiosity on May 19, 2013.

NASA's Curiosity rover is continuing to help scientists piece together the mystery of how Mars lost its surface water over the course of billions of years.

The rover drilled into a piece of Martian rock called Cumberland and found some ancient water hidden within it. Researchers were then able to test a key ratio in the water with Curiosity's onboard instruments to gather more data about when Mars started to lose its water, NASA officials said. In the same sample, Curiosity also detected the first organic molecules it has found. Mission scientists announced the discovery in a news conference today (Dec. 15) at the American Geophysical Union's convention in San Francisco, where they also unveiled Curiosity's first detection of methane on Mars.

"It's really interesting that our measurements from Curiosity of gases extracted from ancient rocks can tell us about loss of water from Mars," Paul Mahaffy, Curiosity's SAM (Sample Analysis at Mars) instrument principal investigator at NASA's Goddard Space Flight Center in Greenbelt, Maryland, said in a statement. [Photos: The Search for Water on Mars]

Curiosity measured the ratio of deuterium (heavy hydrogen) to "normal" hydrogen. This D-to-H ratio can help scientists see how long it takes for water molecules to escape, because the lighter hydrogen molecules fly toward the upper atmosphere more freely than deuterium does.

The D-to-H ratio in Cumberland is about half the ratio found in the Martian atmosphere's water vapor today, NASA officials said. This suggests that the planet lost much of its surface water after the Cumberland rock formed, space agency officials added in the same statement.

But the water sample is also about three times "heavier" than Earth's oceans. This means that if Mars' surface water started off with a D-to-H ratio like Earth's, then most of the Martian water likely disappeared before Cumberland formed about 3.9 billion to 4.6 billion years ago.

The Cumberland measurement fills in a gap for scientists studying different epochs of Martian geological evolution. This sampling marks the first time scientists have been able to measure what the water on Mars may have been like during the Hesperian period, when this rock was formed, said Mahaffy, who is the lead author of a Mars water study published in the journal Science this week.

Previously, scientists have used Martian meteorites on Earth to sample Martian water; however, none of those space rocks date back to the Hesperian period.

"You have the whole period from 2.5 billion to 4 billion years old, and there's no data that we have from Mars meteorites just because we haven't found any yet, I guess," Mahaffy told Space.com. "So, it's very gratifying to be able to fill in that picture a little bit."

Follow Miriam Kramer @mirikramerFollow us @SpacedotcomFacebook and Google+. Original article onSpace.com.

Copyright 2014 SPACE.com, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

You've read  of  free articles. Subscribe to continue.

Dear Reader,

About a year ago, I happened upon this statement about the Monitor in the Harvard Business Review – under the charming heading of “do things that don’t interest you”:

“Many things that end up” being meaningful, writes social scientist Joseph Grenny, “have come from conference workshops, articles, or online videos that began as a chore and ended with an insight. My work in Kenya, for example, was heavily influenced by a Christian Science Monitor article I had forced myself to read 10 years earlier. Sometimes, we call things ‘boring’ simply because they lie outside the box we are currently in.”

If you were to come up with a punchline to a joke about the Monitor, that would probably be it. We’re seen as being global, fair, insightful, and perhaps a bit too earnest. We’re the bran muffin of journalism.

But you know what? We change lives. And I’m going to argue that we change lives precisely because we force open that too-small box that most human beings think they live in.

The Monitor is a peculiar little publication that’s hard for the world to figure out. We’re run by a church, but we’re not only for church members and we’re not about converting people. We’re known as being fair even as the world becomes as polarized as at any time since the newspaper’s founding in 1908.

We have a mission beyond circulation, we want to bridge divides. We’re about kicking down the door of thought everywhere and saying, “You are bigger and more capable than you realize. And we can prove it.”

If you’re looking for bran muffin journalism, you can subscribe to the Monitor for $15. You’ll get the Monitor Weekly magazine, the Monitor Daily email, and unlimited access to CSMonitor.com.