While it's uncertain if NASA's bold plan to return humans to the Moon by 2020 will go down in flames (thanks to the nation's deficit spending on less inspiring things), the space agency continues to take baby steps back to Luna.
Extended to its greatest potential, NASA's Constellation project could potentially jump start America's lagging technological and industrial might; it would involve the labor of hundreds of thousands of men and women-from college researchers and engineers to office staffers and construction workers-all with a magnificent government-industrial-educational team that's grander than Project Apollo. And what's better than a bailout? How about a new world to explore and develop with new technologies not yet imagined.
As part of NASA's first baby steps on the long and uncertain path-a path that leads from cradle Earth, back to the Moon, on to Mars, and beyond-the Lunar Reconnaissance Orbiter, or LRO, has just started mapping the near and farsides of the Moon from an orbit only 31 miles high. LRO has already collected hundreds of detailed images that now make up the first detailed atlas of the Moon's south pole.
So what's so important about creating an atlas of the lunar south pole? Well, just like the Moon's north pole, the south pole is a place that more than likely contains vast deposits of ice left over from the Moon's primordial watery past. These water ice deposits are buried deep below the lunar regolith (soil) within perpetually shadowed craters.
Last week, scientists released LRO's preliminary stream of images and data. The result shows a healthy spacecraft with a lot of work to do. And if all things go well, LRO will continue its vital lunar mission through 2010.
Craig Tooley, NASA's LRO project manager, said the Moon's south polar craters are bitterly cold. The bottoms of these remote craters appear to hold immense deposits of "fossil" water ice, hydrogen, and helium-3 the result of ancient outgassing, cometary impacts, and solar wind deposits.
"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.