A new astronomical study has provided information about the Moon that could change the way future space missions will take place on the satellite. Published last Thursday (25) in The Planetary Science Journal, the research found not only that the Moon has been shrinking over time, but also that earthquakes can occur on its surface.
The study describes that the Moon has shrunk by more than 45 meters in its circumference in hundreds of millions of years. Most likely, this decrease may have led to the formation of faults, which generate earthquakes.
According to the study, the shrinkage of the lunar surface was capable of generating significant deformation in the natural satellite’s south pole, to the point of affecting areas where the manned landings of Artemis 3 — a new mission that would take place in September 2026, to take humans to Moon for the first time in more than 50 years. As a result, some areas of the Moon may pose a danger to future space missions.
“Similar to a grape that wrinkles as it turns into a raisin, the Moon also develops folds as it shrinks,” explains a statement from the University of Maryland, in the United States, involved in the discovery. “But unlike the flexible skin of a grape, the Moon’s surface is fragile, causing faults to form where sections of the crust press against each other.”
According to the statement, to prepare the study, a set of faults at the lunar south pole were linked to earthquakes recorded more than 50 years ago by Apollo Program seismometers. In this way, a simulation of the stability of surface slopes in the region was carried out to identify particularly vulnerable areas.
“Our simulations suggest that shallow lunar earthquakes capable of generating strong ground shaking in the south polar region are possible from slip events on existing faults or the formation of new thrust faults,” said Thomas R. Watters, senior scientist emeritus at the Center for Earth and Planetary Studies of the National Air and Space Museum and main author of the study, also in a statement.
The study also identified that shallow lunar tremors – that is, caused by faults inside the Moon – can be strong enough to damage possible human structures on the satellite, such as buildings and equipment. Furthermore, unlike terrestrial earthquakes, which last a few seconds or minutes, lunar earthquakes can last for hours or even an entire afternoon.
“As we approach the launch date of the crewed Artemis mission, it is important to keep our astronauts, equipment and infrastructure as safe as possible. This work is helping us prepare for what awaits us on the Moon, whether thinking about engineering of structures that can better resist lunar seismic activity or in protecting people from really dangerous areas”, points out, finally, Nicholas Schmerr, co-author of the study and associate professor of geology at the University of Maryland.