"On Dec. 14, 2006, we observed at least five Geminid meteors hitting the Moon," reports Bill Cooke of NASA's Meteoroid Environment Office in Huntsville, AL. Each impact caused an explosion ranging in power from 50 to 125 lbs of TNT and a flash of light as bright as a 7th-to-9th magnitude star. "The amazing thing is," says Cooke, "we've [caught explosions] using a pair of ordinary backyard telescopes, 14-inch, and off-the-shelf CCD cameras. Amateur astronomers could be recording these explosions, too."

"We don't have enough real moondust to go around," says Larry Taylor, director of Planetary Geosciences Institute at the University of Tennessee in Knoxville. To run all the tests, "we need to make a well-qualified lunar simulant." And not just a few bags will do. "We need tons of it, mainly for working on technologies for diggers and wheels and machinery on the surface," adds David S. McKay, chief scientist for astrobiology at the Johnson Space Center (JSC).