Although almost all volcanic activity on the Moon stopped billions of years ago and it is a dead Earth satellite with rare geological activity, earthquakes occasionally occur on it, as well as on our and other planets, NASA scientists said.
They claim that due to internal cooling over the past few hundred million years, this celestial body has shrunk by 50 meters and is still tectonically active.
Gradually the "shrinking" Moon becomes wrinkled.
Scientists have likened it to the "shrinking" of a grape grain, which shrinks and wrinkles as it turns into a raisin.
But unlike the flexible skin of a grape, the Moon's surface skin is fragile, so it falls apart when it shrinks.
These phenomena occur when the crust moves and pushes one part over the other. In doing so, unusual rocks are formed that can be seen on the surface. They are high and kilometers long, Hina agency reports.
Rocks that were scattered earlier left a mark on the entire surface, and new data from the NASA mission indicate that earthquakes still occur along these cracks today.
New research was made possible by algorithms that processed seismic data from the sixties and seventies of the last century, which contributed to the illumination of tectonic activity on the Moon and their better understanding.
Four types of earthquakes have long been known to occur on the Moon - the first three types are deep earthquakes caused by meteorite collisions or thermal shocks caused by the Sun's heat, but these are relatively weak.
The fourth type of so-called "shallow" earthquakes is more powerful and can reach a magnitude of up to 5,5 on the Richter scale and can last up to 10 minutes.
"We concluded from the analysis that this kind of activity is still present and that it probably causes earthquakes even today when the Moon is still gradually cooling and shrinking," said Thomas Waters, a senior scientist at the Center for Earth and Planetary Studies at the University of Washington.
He also states that "some earthquakes are quite strong and measure up to 5,5 degrees on the Richter scale".
The scientists compared the obtained data with images taken in 2010 by NASA's linear orbiter.
Instruments left on the Moon by Apollo 11 astronauts from 1969 to 1977 recorded 28 different earthquakes.
Scientists have established that at least eight earthquakes are the result of the movement of plates under the surface of the Moon, and not the impact of an asteroid, reports Hina.
They claim that the shaking and contraction of this celestial body continues today, and photos of rocks and landslides on the surface point to recent tectonic activity.
NASA states that earthquakes occur at the moment when the Moon is at its farthest point from the Earth because the Earth's gravity damages its crust.
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