According to the Global Times, citing CNN on January 31**, a study funded by the National Aeronautics and Space Administration (NASA) found that as the interior of the moon gradually cools and contracts, the moon's south pole will produce moonquakes and faults, which may pose a threat to future human lunar exploration missions.
A study published in the Journal of Planetary Science reports that over the past few million years, the Moon has shrunk and its circumference has decreased by about 46 meters.
Like a grape shrinking into a raisin, the moon shrinks into folds on its surface. However, unlike the elastic grape skin, the surface of the moon is fragile, so when the moon shrinks, the earth's crust pushes against each other, forming faults.
Because the faults created by the shrinking moon are often accompanied by activities such as moonquakes, fault zones or nearby areas can be dangerous for human lunar exploration, the report said. Researchers said that the U.S. "Apollo 11" deployed on the moon more than 50 years ago recorded a strong moonquake, which occurred near the fault zone at the south pole of the moon.
We know from the Apollo experiments that there are 4 instruments that have been in operation for about 7 years, that is, there are these shallow moonquakes on the moon, but we don't actually know what the hypocenter is. The study's lead author, Thomas R. Waters, a senior scientist emeritus at the National Air and Space Museum's Center for Earth and Planetary Studies"We also know that the largest shallow moonquake detected by the Apollo instrument is near the moon's south pole. It's a bit like a detective story trying to find the source. ”
According to the report, the strongest ** recorded on the moon is equivalent to 5Level 0. On Earth, that's considered modest, but the moon's lower gravity makes people feel worse, Waters said, "On Earth, you have a stronger gravity for you to attach to the surface." On the Moon, it's much smaller, so even a little ground acceleration can make you fall if you walk. In a low-gravity environment, this shaking can really cause things to fly. ”
Schmill, an associate professor of geology at the University of Maryland in the United States, said the results of the study mean that future settlements planned to be built on the moon could be damaged by shallow moonquakes.
This is not to alarm anyone, and certainly not to prevent exploration of that part of the moon's south pole. "But be warned, the moon isn't a good place where nothing happens." ”
It is believed that the Moon is a geologically dead object that has not happened for billions of years, but this could not be further from the truth. "These faults are very young and happening. In fact, we have detected landslides that occurred during the orbit of the Lunar Reconnaissance Orbiter. ”
Although the magnitude of the decrease in the circumference of the Moon is a large number from a geological point of view, it is still too small from an astronomical point of view to have any ripple effects on the Earth or the tidal cycle.