What can we learn from a chunk of rock known as NWA 7034? The rubble was blasted off the surface of Mars eons ago. After it made the long, cold journey to Earth, it slammed into the Sahara desert as a meteorite.

"We know that Mars may have been warm and wet very early in its history," says Carl Agee, the lead author of a new report in the journal Science. "But this sample suggests the water may have lingered much longer than anyone realized."

A meteorite collector handed NWA 7034 to Agee in 2011. It was clear that even among Mars rocks, this one was special. It had an unusual color and texture, and 10 times the water content of other meteorites from Mars. "I'd never seen anything like it," says Agee.

The sample has had more than a year of analysis by labs across the U.S. and in China. The analysis shows that NWA 7034 is 2.1 billion years old. This places it in an era long after the water was supposed to have vanished from Mars.

Scientists say they need more time to study the rock. "There's always more than one way to explain something like this," Agee cautions. "We've got 10 labs working on this meteorite right now. This was just NWA 7034's debut."

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