Did our planet once have two moons? Some researchers say so. Moreover, the missing satellite might still be up there--splattered against the far side of the Moon. NASA's GRAIL mission, due to launch on Sept. 8th, could help confirm or refute the "two moon" hypothesis.
FULL STORY at
http://science.nasa.gov/science-news/science-at-nasa/2011/07sep_twomoons/
