Why Do Lunar Satellites Eventually Crash into the Moon?

Spacecraft orbiting the Earth have remained in space since the 1950’s and may last for centuries more, but spacecraft orbiting close to the moon can crash within weeks. The reason for this is the lunar gravity field is lumpy, with geological features making the smooth orbits of space probes distort until they hit the surface. The recent publication on the giant lunar and images taken from NASA’s Apollo, GRAIL and LRO programs.

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