Violent past revealed by map of moon’s interior
Gravity survey reveals churned-up layers just beneath lunar surface
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SAN FRANCISCO — The moon is cooling and shrinking today, but early in its history it actually got bigger, scientists have found.
As the moon expanded, molten rock rose from its deep interior to cool and solidify into long gashes buried beneath the surface. For billions of years these fiery scars remained hidden, finally revealing themselves to a pair of spacecraft flying overhead.
The probes, named Ebb and Flow, spotted the rock formations by their gravitational pull. And not just that: the NASA mission has revealed a host of other discoveries, both on the moon’s surface and below it. In producing the best gravity map ever compiled of any planet or moon — Earth included — the mission illustrates how violently the moon’s crust was pummeled by meteorites over eons.