LOS ANGELES — The moon is much wetter and more chemically complicated than scientists had believed, according to data released Thursday by NASA.
Last year, after the space agency dropped a rocket into a frozen crater near the moon's south pole and measured the stuff kicked up by the collision, scientists calculated that the crater contained about 25 gallons of water. But further analysis over the past 11 months indicates that the amount of water vapor and ice was closer to 41 gallons.
"It's twice as wet as the Sahara Desert," said Anthony Colaprete, the lead scientist for the Lunar Crater Observation and Sensing Satellite (LCROSS) mission at NASA Ames Research Center in northern California.
The instruments aboard the satellite, including near-infrared and visible light spectrometers, scanned the debris cloud and identified the compounds it contained. They determined that about 5.6 percent of the plume was made of water, give or take 2.9 percent. It also included a surprising variety of chemicals, including mercury, methane, silver, calcium, magnesium, pure hydrogen and carbon monoxide.
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The findings were reported in six related papers published online Thursday by the journal Science.
"The lunar closet is really at the poles, and I think there's a lot of stuff crammed into the closet that we really haven't investigated yet," said Peter Schultz, a planetary geologist at Brown University and one of the LCROSS team members.
The new measurements allowed Colaprete to estimate that the Cabeus crater could hold as much as 1 billion gallons of water.
That might be handy for space explorers who might use the moon as an interplanetary way station. The water could be used for drinking and be mined for breathable oxygen. It also could be used to make hydrogen fuel for long-distance spacecraft.
"You can't take a lot of big things to the moon and you can't take much water, so we're learning to live off the land," said Lawrence Taylor, a planetary geochemist at the University of Tennessee in Knoxville, who was not involved in the studies.
For scientists studying the evolution of the moon, equally intriguing was the finding was the assortment of chemicals detected in the plume. Not all of the hydrogen was attributable to water.