Why Scientists Think the Moon Is Shrinking
Is there less of the moon to love than there used to be?
Yesterday came the news that our natural satellite might have shrunk 100 meters in diameter in relatively recent geologic time. The Lunar Reconnaissance Orbiter found a plethora of scarps across the lunar surface, far more than we knew about before. These cliff-like features can appear on Earth from tectonic shifts, but there’s no continental drift on the moon. Thus, the most likely explanation is: The moon shrunk. If it did, the surface would buckle under the pressure and create these scarps. Astronomers say that the gradual cooling of the moon’s interior probably caused the shrinkage.
Don’t worry about the tides disappearing, though. “Recent” means a different thing to geologists than to everyone else, and in this case it has taken a billion years for the moon to shrink in diameter just 0.003 percent.
For plenty more on the find, check out Phil Plait’s post at Bad Astronomy.