water found on the moon

July 9, 2008 -- A new analysis of Apollo 15 moon rocks has for the first time uncovered water locked up inside.

It's just a miniscule amount of the wet stuff -- not enough to sustain even a lunar cactus or to power any hydrogen jetpacks -- but the discovery does bolster hopes that there has always been water in moon rocks and perhaps some locked away as ice in the dark crannies of polar craters.

The discovery also overturns 40 years of studies which had failed to find the water and which led to the conclusion, drawn by most planetary scientists, that moon rocks must be all dry.

"Folks said it was a waste of time," said lead researcher Alberto Saal of Brown University, regarding their proposal to look at the moon rocks one more time. "It took us three years to get it funded."

Still, using a refinement of a method called secondary mass spectrometry, Saal and his colleagues eventually were able to count molecules two orders of magnitude lower than in the past -- down to just four or five of water molecules per million. As it turned out, they found up to 46 parts per million in tiny volcanic glass balls brought back from the moon.

What really makes the case that this is truly old lunar water -- and not water made from hydrogen blasted from the sun into the moon rocks -- is the manner water is distributed inside the volcanic glass balls. Saal and his team found more water in the middle and less nearer the rims of the balls.

The only way for that to happen is if the water was in the rocks when they originally flowed out of lunar volcanoes and has been gradually diffusing away -- and perhaps some settling in cold dark craters -- over the billions of years since the rocks solidified.
-courtesy discovery.com