NASA has selected a new mission to measure the Moon's gravity field in unprecedented detail, according to the agency's associate administrator for science, Alan Stern. The Gravity Recovery and Interior Laboratory (GRAIL), which is part of NASA's Discovery Program series of scientist-led, solar system exploration missions, is scheduled to launch in 2011 following the agency's 2008 launch of the Lunar Reconnaissance Orbiter. Scientists plan to use gravity field information from GRAIL's two spacecraft to X ray the Moon from crust to core to reveal subsurface structures and, indirectly, the Moon's thermal history. A camera aboard each spacecraft will allow the public to see observations from the satellites. GRAIL “offers to bring innovative Earth studies techniques to the Moon as a precursor to their possible later use at Mars and other planets,” Stern said. For more information, visit the Web site: