Shrinking Moon can risk Artemis mission with quakes & landslides: Study

New York, Jan 26: Even as Earth's Moon continues to shrink, it may cause landslides and quakes in the lunar South Pole -- the potential landing site for the Artemis mission, according to a team of scientists.

Earth’s moon shrank more than 150 feet in circumference as its core gradually cooled over the last few hundred million years. As the moon’s surface is brittle, it can cause faults to form where sections of crust push against one another increasing risks for astronauts.

Scientists discovered evidence that this continuing shrinkage of the moon led to notable surface warping in its south polar region -- including areas that NASA proposed for crewed Artemis III landings in 2024.

Because fault formation caused by the moon’s shrinking is often accompanied by seismic activity like moonquakes, locations near or within such fault zones could pose dangers to future human exploration efforts.

In the paper published in the Planetary Science Journal, the team linked a group of faults located in the moon’s south polar region to one of the most powerful moonquakes recorded by Apollo seismometers over 50 years ago.

Using models to simulate the stability of surface slopes in the region, the team found that some areas were particularly vulnerable to landslides from seismic shaking.

“Our modelling suggests that shallow moonquakes capable of producing strong ground shaking in the south polar region are possible from slip events on existing faults or the formation of new thrust faults,” said lead author Thomas R. Watters, a senior scientist in the National Air and Space Museum’s Center for Earth and Planetary Studies.

“The global distribution of young thrust faults, their potential to be active and the potential to form new thrust faults from ongoing global contraction should be considered when planning the location and stability of permanent outposts on the moon,” he added.

Shallow moonquakes occur near the surface of the moon, just a hundred or so miles deep into the crust. Similar to earthquakes, shallow moonquakes are caused by faults in the moon’s interior and can be strong enough to damage buildings, equipment and other human-made structures.

But unlike earthquakes, which tend to last only a few seconds or minutes, shallow moonquakes can last for hours and even a whole afternoon -- like the magnitude 5 moonquake recorded by the Apollo Passive Seismic Network in the 1970s, which the research team connected to a group of faults detected by the Lunar Reconnaissance Orbiter more recently.

This means that shallow moonquakes can devastate hypothetical human settlements on the moon, said a co-author Nicholas Schmerr, Associate Professor of geology at the University of Maryland.

The researchers continue to map out the moon and its seismic activity, hoping to identify more locations that may be dangerous for human exploration.