The Moon responds elastically to Earth’s gravity. As it orbits, Earth’s pull slightly deforms the Moon. This creates tiny gravity waves within its structure. Instruments can measure these changes precisely. They help map the Moon’s interior. Even solid rock isn’t truly rigid.
This matters because it reveals internal layering. Scientists can infer core size and composition. That helps explain lunar evolution.
It also improves navigation and landing accuracy. Gravity models must be precise. Small forces matter in space.
The Moon’s shape changes by about 10 centimeters due to tidal forces. That’s measurable from Earth.
NASA [nasa.gov]