From Crust to Core, GRAIL Reveals the Lunar Interior
Feb. 17 & 18
The Moon is the most accessible and best studied rocky, or "terrestrial", body beyond Earth. Unlike Earth, however, the Moon's surface has preserved the record of nearly the entire 4.5 billion years of solar system history. Orbital observations and samples of surface rocks returned to Earth show that no other body preserves the record of geological history as clearly as the Moon. And yet, there is still a great deal we do not yet understand. Questions about the origin of the maria and the asymmetry in crustal thickness require more advanced studies to understand. By carefully studying the gravity of the moon, its interior structure and thermal evolution can be learned. This information can then be extended beyond the moon to help us further understand the history and evolution of the other terrestrial planets in our solar system. NASA's Gravity Recovery and Interior Laboratory, or GRAIL, will use a technique pioneered by a highly successfully Earth mission, called GRACE, and will place two spacecraft in a low-altitude, nearly circular orbit around the moon to help reveal the answers to these intriguing questions.
Sami Asmar, GRAIL Deputy Project Scientist, JPL (And, perhaps, Mike Watkins, GRAIL Project Scientist, JPL)