http://www.msnbc.msn.com/id/33912611/ns ... nce-space/
It's official: There's water ice on the moon, and lots of it. When melted, the water could potentially be used to drink or to extract hydrogen for rocket fuel.
NASA's LCROSS probe discovered beds of water ice at the lunar south pole when it impacted the moon last month, mission scientists announced Friday. The findings confirm suspicions reported previously, and in a big way.
"Indeed, yes, we found water. And we didn't find just a little bit, we found a significant amount," said Anthony Colaprete, LCROSS project scientist and principal investigator from NASA's Ames Research Center at Moffett Field, Calif.
The LCROSS probe impacted the lunar south pole at a crater called Cabeus on Oct. 9. The $79 million spacecraft, preceded by its Centaur rocket stage, hit the lunar surface in an effort to create a debris plume that could be analyzed by scientists for signs of water ice.
Those signs were visible in the data from spectrographic measurements (which measure light absorbed at different wavelengths, revealing different compounds) of the Centaur stage crater and the two-part debris plume created by the impact. The signature of water was seen in both infrared and ultraviolet spectroscopic measurements.
"We see evidence for the water in two instruments," Colaprete said. "And that's what makes us really confident in our findings right now."
How much?
Based on the measurements, the team estimated that there was about 220 pounds (100 kilograms) of water in the view of their instruments, which took in the area of the impact crater (about 80 feet or 20 meters across) and the ejecta blanket (about 200 to 260 feet across, or 60 to 80 meters), Colaprete said. That amount of water is roughly the equivalent of a dozen 2-gallon buckets.
"I'm pretty impressed by the amount of water we saw in our little 20-meter crater," Colaprete said.
"What's really exciting is we've only hit one spot. It's kind of like when you're drilling for oil. Once you find it one place, there's a greater chance you'll find more nearby," said Peter Schultz, professor of geological sciences at Brown University and a co-investigator on the LCROSS mission.
This water finding doesn't mean that the moon is wet by Earth's standards, but is likely wetter than the driest deserts on Earth, Colaprete said. And even this small amount is valuable to possible future missions, said Michael Wargo, chief lunar scientist for Exploration Systems at NASA Headquarters.
Scientists have long suspected that permanently shadowed craters at the south pole of the moon could be cold enough to keep water frozen at the surface, based on detections of hydrogen by previous moon missions. Water has already been detected on the moon by a NASA-built instrument on board India's now-defunct Chandrayaan-1 probe and other spacecraft, though it was in very small amounts and bound to the dirt and dust of the lunar surface.
Water wasn't the only compound seen in the debris plumes of the LCROSS impact.
"There's a lot of stuff in there," Colaprete said. What exactly those other compounds are hasn't yet been determined, but the ingredients could include organic materials that would hint at comet impacts in the past.
