Moonquakes were discovered by Apollo astronauts. Seismometers placed on the surface recorded them. Some quakes are caused by tidal stresses from Earth. Others come from meteorite impacts. The strongest moonquakes can last up to 10 minutes. Unlike Earth, the Moon lacks water to dampen vibrations. Shaking travels farther.
This matters because it reveals internal structure. The Moon isn’t completely rigid. Its interior still responds to forces.
It also helps future missions. Structures must withstand moonquakes. Safety planning depends on this knowledge.
The strongest moonquakes occur when the Moon is farthest from Earth.
[NASA, nasa.gov]