Friday December 30, 2011
What is the moon made of? NASA seeks to find out
Two robotic NASA probes are due to arrive at the moon this weekend to resolve a long-standing mystery of what is inside Earth’s natural satellite and how it got there.
The 303-kilogram craft of the U.S. space agency’s Gravity Recovery and Interior Laboratory, or GRAIL, mission have been flying to the moon since their joint launch in September. (Photo: Apollo 16/NASA)
GRAIL A is due to begin a 40-minute braking maneuver to put itself into orbit around the moon at 4:21 p.m. ET on Saturday, with GRAIL B following suit 25 hours later. Both are needed for the intricate gravity-mapping mission scheduled to begin in March.