On Monday, the scientists dropped in claiming that the moon is shrinking resulting in moonquakes which have been recently detected. Nicholas Schmerr (a geologist at the University of Maryland) said, “As the moon cools, its overall size decreases by about 100 meters which is why we say it is shrinking. This puts the crust under compression which compels the surface to deflate and flatten. If there is any compressing stress, the crust can fail, producing earthquakes- or in this case moonquakes.”
The lead author of Smithsonian Institution’s National Air and Space Museum, Thomas Watters claimed that some of these quakes can be fairly strong, around five on the Ritcher scale. Some of the quakes occurred when it was farthest from the earth. Scientists assume this to be caused by the tidal stress of earth’s gravity on the moon.
“Establishing a new network of seismometers on the lunar surface should be a priority for human exploration of the Moon, both to learn more about the Moon’s interior and to determine how much of a hazard moonquakes present,” claimed Renee Weber, the co-author and planetary seismologist at NASA’s Marshall Space Flight Center.
In order to know more about the quakes, its origin, and causes, the scientists went back the data collected between the latter and early years of 1960 and 1970 respectively by the Apollo Astronauts. The researchers comparatively studied this along with new information from NASA’s Lunar Reconnaissance Orbiter present around the moon.
The crust or outer layer of the moon’s surface is brittle because of this, the crust breaks as the moon shrinks, causing “thrust faults”. During thrust faults, one area or part of the crust is impelled over an adjacent part. Providentially, the moon’s mass is unaffected “and the radiance of change is so small, so the effect on Earth is minuscule, and it won’t affect tides or make the moon disappear,” stated Schmerr.