Scientists examining a 2 billion-year-old rock from Mars that landed in the Sahara desert say it holds a large amount of water for a Martian meteorite.
Experts at the University of New Mexico say the rock has about 30 times the water of other Mars meteorites. They say this could lead to a better understanding of how Mars turned from a warm moist planet into a cold and dusty desert.
The scientists also say the rock is very similar to the volcanic rocks found by NASA's Spirit and Opportunity Mars rovers.
A Moroccan man found the meteorite in the Sahara desert last year. He sold it to an American collector who turned it over to the university for study.
Scientists are calling the rock a one-of-a-kind specimen.