Isle-linked mission alters view of Earth's celestial neighbor


POSTED: Saturday, November 14, 2009

Water discovered by the LCROSS mission in a lunar crater “;changes our view of the moon forever,”; says a University of Hawaii astronomer.

The discovery of about 25 gallons of water after the LCROSS spacecraft and a companion rocket crashed into the moon Oct. 9 “;shows for the first time that the moon is not a completely dry place,”; said Alan Tokunaga, chief of the NASA Infrared Telescope Division of the Hawaii Institute for Astronomy.

“;It's not a huge amount,”; said John Rayner, staff scientist responsible for instrumentation at the Infrared Telescope Facility on Mauna Kea, operated by UH and NASA. “;It's still very dry by terrestrial standards.

“;But that kind of water vapor could be used as a resource,”; he said. “;It's getting to a level where they could think about using this soil and heating it up and driving off water vapor.”; It could be cooled down and water purified from it to use for drinking or rocket fuel, he said.

The Infrared Facility was among Mauna Kea observatories studying the LCROSS event. Rayner built a spectrograph used on the telescope to look for clues of water during the mission.

The rocket hit the moon's Cabeus crater, which was recorded by the shepherding spacecraft before crashing four minutes later into the same spot.

Two plumes occurred, one straight up and another to the side, Rayner said. Both infrared and ultraviolet instruments on the spacecraft detected water, he said.

He said he does not think much will come from ground-based observations, but the mission worked from NASA's point of view. The major goal was to find evidence of water that could be used for a human base on the moon.

Tokunaga said there were a lot of reasons to believe the moon had water. The area targeted by LCROSS “;is very cold because it is in the shadow of the crater, and gases have been condensing there for perhaps a billion years or more,”; he said.

“;But there are also features in the spectrum that are as strong as the water. This is really interesting and suggests that perhaps other kinds of gases have also been condensing there. ... This is a very exciting discovery.”;