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Impact reveals lunar water by the bucketful

NASA's LCROSS mission has confirmed an icy store of water at the moon's south pole

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EVERYWHERE? Not quite, but NASA’s LCROSS mission did kick up a few bucketfuls after all when it collided with the moon.

On 9 October, the LCROSS team smashed a spent rocket stage into the moon. The idea was to kick up a plume of material that could be analysed for water.

Earth-based observers had trouble seeing the ejecta, partly because it was hidden by a ridge. The shepherding spacecraft told a different story: it followed the rocket stage on its collision course, and on the way measured more than 100 kilograms of water ice in the part of the plume it observed. “We didn’t find just a little bit. We found a significant amount,” says LCROSS principal investigator Anthony Colaprete of NASA’s Ames Research Center in Moffett Field, California.

This confirms that the moon’s poles contain stores of water ice – more than the traces found by India’s Chandrayaan-1 probe in September. “LCROSS has now made that definitive discovery, says Greg Delory of the University of California, Berkeley.

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