Google and the X Prize Foundation have announced that 10 teams will compete in the Google Lunar X Prize, which requires contestants to land a privately funded robotic spacecraft on the moon, explore the terrain for at least 500 meters, and transmit results of the trip back to Earth. A team that accomplishes the mission before Dec. 31, 2012, will be eligible for a $20 million prize. The second-place team wins $5 million. If it takes until 2013, the grand prize amount drops to $15 million. The contest ends on Dec. 31, 2014, unless both organizations decide to extend it.