Los Angeles AP
The moon took quite a beating in its early days, more than previously believed, scientists reported Wednesday.
This surprising new view comes from detailed gravity mapping by twin spacecraft that slipped into orbit this year. Evidence of a highly fractured lunar interior just below the surface suggests that other rocky planets, including Earth, would have suffered similar bombardment from space rocks early in their history.
Measurements by NASA's Ebb and Flow spacecraft — the first probes dedicated primarily to measuring lunar gravity — also found that the moon's crust is much thinner than scientists thought, only 40 km thick.
To collect data, the washing machine-size spacecraft flew in formation, orbiting about 55 km above the moon's surface, allowing them to peer deep into the moon. The spacecraft also managed to see landforms on the moon in greater detail than before, including volcanoes, basins and craters.
The mission is scheduled to end later this month when Ebb and Flow crash into the moon.