
Gravity Map Reveals a Surprisingly Battered Lunar Surface
The moon and other rocky bodies in the inner solar system were pounded by long-ago impacts far more violently than previously thought, two NASA spacecraft have found.
NASA’s Gravity Recovery and Interior Laboratory (GRAIL) made this new high-resolution map of the moon’s gravity field. Credit: NASA/JPL-Caltech/MIT/GSFC
NASA’s twin Grail probes have created an ultra-precise gravity map of the moon, revealing that its crust is almost completely pulverized. The surprising find suggests that Earth, Mercury, Venus and Mars endured a similar beating billions of years ago, researchers said.
The discovery “really opens a window to this early stage of just what a violent place the surfaces of all terrestrial planets were early in their history,” Grail principal investigator Maria Zuber of MIT said during a press conference here today (Dec. 5) at the annual fall meeting of the American Geophyiscal Union.

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