New scans show evidence of water on the moon

Reuters (Wed 9th July 2008) says: Scientists have reported that tiny green and orange glass balls brought back from the moon nearly 40 years ago by astronauts show evidence that water existed there from the very beginning.

They used a new method of analysing elements in the lunar sand samples to show strong evidence of water, dating back 3 billion years.

Their study, published in the journal Nature, could support evidence that water persists in shadowed craters on the moon's surface - and that the water could be native to the moon and not carried there by comets.

Most scientists believe the moon was formed when a Mars-size body collided with the Earth 4.5 billion years ago. The giant impact would have melted both proto-planets and sent molten debris into orbit around the Earth.

Some of this would have eventually coalesced into the moon, but the heat of the impact would have vaporised light elements such as the hydrogen and oxygen needed to make water - theoretically, anyway.

Erik Hauri of the Carnegie Institution for Science in Washington had developed a technique called secondary ion mass spectrometry or SIMS, which could detect minute amounts of elements in samples. His team was using it to find evidence of water in the Earth's molten mantle.

"Then one day I said, 'Look, why don't we go and try it on the moon glass?'" Alberto Saal of Brown University, who helped lead the study, said in a telephone interview.

"It took us three years to convince NASA to fund us."

Professor Saal's team did not find water directly, but they did measure hydrogen, and it resembled the measurements they have done to detect hydrogen, and eventually water, in samples from Earth's mantle.