* Frequency:
* Shallow moonquakes (less than 30 km deep): Occur about 1,000 times a year.
* Deep moonquakes (over 700 km deep): Occur much less frequently, perhaps a few dozen times per year.
* Magnitude: Most moonquakes are weak, with magnitudes less than 2.0 on the Richter scale. The largest recorded moonquake had a magnitude of 5.5.
* Causes:
* Tidal forces from Earth: The main cause of shallow moonquakes.
* Meteoroid impacts: Can trigger both shallow and deep moonquakes.
* Stress from the Moon's interior: The cause of deep moonquakes, which are thought to be related to the Moon's cooling and contraction.
It's important to note that these are estimates based on the limited data we have from seismometers placed on the Moon during the Apollo missions. More research is needed to get a more complete understanding of moonquakes.
