The study revealed that the Moon’s circumference has shrunk by about 46 meters over the past millions of years, which is a large number in geological terms, but too small to cause any ripple effect on Earth or tidal cycles, according to the researchers.
The author of the study, lunar geologist Tom Waters, says: “I think the prevailing concept among many people is that the Moon is a geologically dead body, and that something on the Moon never changes. But the truth is that the Moon is a seismically active body,” according to the American newspaper “The Washington Post.” .
He added: “When the moon cools, it shrinks and the internal volume changes. The crust must adapt to this change. It is a global contraction in which tidal forces contribute, just as it happens on Earth.”
He explained: “The shrinkage of our moon has minimal effects on Earth. A change in size will not change the occurrence of an eclipse, for example. Also, its mass does not change, so the tides on Earth are not affected differently.”
He continued: “There is no reason for Earthlings to be concerned about the shrinkage of the Moon, unless we move there.”
Does the shrinking moon cause earthquakes?
- Studies of lunar earthquakes go back to the Apollo era, more than 50 years ago, when astronauts placed seismometers around the near side of the moon’s surface to record tremors.
- The strongest shallow earthquake occurred near the South Pole, which is close to the landing points for NASA’s Artemis 3 mission to return people to the moon, likely in 2027.
- It’s different on the moon. Despite what its appearance might suggest, the moon still has a hot interior that makes it seismically active.
- Watters and his colleagues report that the last strong earthquake was associated with a set of currently seismically active faults, which originated as the Moon contracted, much of this contraction driven by the natural cooling of the Moon’s molten core.
- “Moonquakes differ from terrestrial earthquakes in several key ways,” Watters explained. “They can last longer on the Moon, sometimes hours. This is due to the Moon’s weaker gravity, so the earthquake is much stronger than one that occurs on Earth.”
The south pole of the moon
- The lunar South Pole region is attractive because it has permanently shaded areas, some speculate, and could contain water ice.
- Like the rest of the Moon’s natural surface, the Antarctic region is vulnerable to seismic events, making it less hospitable for living and posing a threat to future human and equipment settlers.
- Interest in the lunar south pole soared last year, when India’s Chandrayaan 3 mission made the first successful soft landing in the region, just days after Russia’s Luna 25 spacecraft crashed on its way to attempt the same feat.
- NASA has chosen the area as a landing site for the Artemis 3 mission, which could mark the return of astronauts to the moon as soon as 2027, and China also has plans to establish future missions there.
