AUSTIN (KXAN) – Ever think the moon looks smaller than it used to? Well, it might actually be. The moon is shrinking, according to a new study published by NASA, and in the process, is suffering from “moonquakes”.
Here’s what scientists think is happening:
Much like the center of the earth, the core of the moon is very hot. Over time it has begun to cool, and much like a grape shriveling up into a raisin, the moon is starting to shrivel up as well. The lunar body is now 164 feet skinnier than it was in the 1970’s, the last time humans walked on its surface.
During those missions to the moon, astronauts placed several seismometers on its surface. These devices were used to measure activity beneath the crust. The seismometers measured 28 moonquakes between 1969 and 1977, when astronauts last checked them.
When the moon quakes, there are visible signs. Unlike Earth, the surface of the moon is made up of one large crust. As the moon shrivels, the crust breaks and snaps, creating wrinkles known as “thrust faults.”
These faults resemble stair-shaped cliffs. They’re tens of yards high and miles long. NASA has detected more than 3,500 of these faults forming since 2009.
Eight moonquakes that occurred during the Apollo missions occurred near a thrust fault. Six of those eight occurred when the moon was the farthest distance from the earth.
What this is all means is the moon is still tectonically active. The data could help us understand other bodies in our solar system, but is also leading to more questions about what happens to the moon as it ages.