GRAIL Unwraps the Moon
Dec. 6 & 7
The Gravity Recovery and Interior Laboratory lunar mission has completed its primary period of scientific observations and obtained unprecedented results on the global gravitational field of the Moon. The interior structure of our nearest neighbor has been revealed and models are becoming available to describe the Moon from the crust to the core. Since the Moon shows only one side to Earth, measuring its gravity field at the nearside and far side required the utilization of a pair of mirror-identical spacecraft with radio links between. The links provided precision measurements of how the distance between them changed as they flew over features of varying densities.