Out of the shadows

"The deposits may have accumulated in these cold-trap regions over billions of years," Tooley said last week. "If enough of these resources exist to make mining practical, future long-term human missions to the moon potentially could save the considerable expense of hauling water from Earth." In 1998, NASA's Lunar Prospector spacecraft confirmed significant amounts of hydrogen at the south pole; the gas deposits are the tell-tale sign of water-ice.

LRO's Diviner instrument has shown that inside the shadowed polar craters, the mercury plunges to minus 400 degrees Fahrenheit (33 Kelvin)-a perfect, billion-year-old ice box environment for the storage of primeval water and hydrogen.

LRO's camera is dedicated to imaging these permanently shadowed regions while the craft's Lyman Alpha Mapping Project instrument (LAMP for short), is sniffing for surface ice, even frost. LAMP is so sensitive that it uses starlight and the glow of interplanetary hydrogen emission, to image the perpetually dark polar craters.

A 2008 surprise discovery of water residue inside Apollo 17 lunar volcanic glasses hints of a time, in the remote past, when our Moon possessed as much water as the Caribbean Sea.

What's in the Sky: Looking east, along the edge of Leo, the planets Mercury, Venus and Saturn will line up along the ecliptic Sept. 26. You can see the trio just before sunrise (see sky map).

Lou Varricchio, M.Sc., is a NASA JPL Solar System Ambassador in Vermont. He was a NASA senior science writer at the space agency's Ames Research Center in California.

Vote on this Story by clicking on the Icon


Use the comment form below to begin a discussion about this content.

Sign in to comment