Gravity Recovery and Interior Laboratory (GRAIL)

The Gravity Recovery And Interior Laboratory (GRAIL) will unlock the mysteries of the Moon. By mapping the lunar gravitational field globally —not just on the nearside —to unprecedented accuracy and resolution, GRAIL will, in essence, peer deep inside the Moon to reveal its internal structure and thermal history. Knowledge acquired about the Moon from GRAIL will be extended to understand the broader evolutionary histories of the other rocky planets in the inner solar system: Earth, Venus, Mars, and Mercury. Indeed, the Moon is a lynchpin for understanding how the terrestrial planets evolved.