NASA revealed that the moon is gradually shrinking over the last several hundred million years, hence causing wrinkles in its crust leading to moonquakes.
Unlike the flexible skin on a grape, the Moon’s surface crust is brittle, so it breaks as the Moon shrinks, forming “thrust faults” where one section of crust is pushed up over a neighboring part.
“NASA analysis gives the first evidence that these faults are still active and likely producing moonquakes today as the Moon continues to gradually cool and shrink,” said Thomas Watters.
The images revealed that the quakes are still occurring on the moon, making it actively changing. The algorithm gave a better estimate of moonquake locations.
Seismometers are instruments that measure the shaking produced by quakes, recording the arrival time and strength of various quake waves to get a location estimate, called an epicenter.
The Moon isn’t the only world in our solar system experiencing some shrinkage with age. Mercury has enormous thrust faults up to about 600 miles long and over a mile high that are significantly larger relative to its size than those on the Moon, indicating it shrank much more than the Moon.