The Moon, although not noticeable from Earth, is gradually shrinking as it cools down over time. While the rate of shrinkage is relatively slow at approximately 45 meters every few hundred million years, a recent study conducted by researchers in the United States suggests that this phenomenon could have significant implications for potential landslides and earthquakes near the lunar South Pole. What makes this research particularly crucial is its relevance to NASA’s plans of sending astronauts to the Moon in the future. Establishing a space station in a geologically unstable zone could pose substantial risks. Planetary scientist Tom Watters from the Smithsonian Institution highlights 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.” Therefore, when considering the location and stability of permanent outposts on the Moon, it is vital to take into account the global distribution of young thrust faults and their potential for activity, as well as the possibility of new thrust fault formation resulting from ongoing global contraction.
Research on Lobate Scarps
Conducting research on lobate scarps, extended ridges believed to be caused by tectonic activity, the study primarily utilized recent imagery from the Lunar Reconnaissance Orbiter and data from seismometers deployed during the Apollo missions. The analysis linked one of the most powerful moonquakes ever recorded by the Apollo seismometers to a lobate scarp near the Moon’s South Pole. This magnitude 5 quake which lasted for several hours suggests that even a minor trigger can result in a significant landslide on the Moon. Geologist Nicholas Schmerr from the University of Maryland explains that the Moon’s surface consists of loose, reworked sediment ranging from microns to the size of boulders due to impacts from asteroids and comets over billions of years. These sediments, being loosely consolidated, make the occurrence of shaking and landslides highly probable.
Implications for Future Lunar Landings and Bases
At present, scientists are limited in terms of data regarding the frequency and location of moonquakes. Nevertheless, insights gained from studies like this one are invaluable in planning future Moon landings and lunar bases. As we draw closer to the crewed Artemis mission’s launch date, ensuring the safety of astronauts, equipment, and infrastructure becomes of paramount importance. Schmerr emphasizes the significance of taking all necessary precautions: “It’s important to keep our astronauts, our equipment, and infrastructure as safe as possible.”
The Moon’s shrinking size as it cools down over time has implications for potential landslides and earthquakes near the lunar South Pole. The presence of lobate scarps, believed to be caused by tectonic activity, suggests a link between lunar surface features and moonquakes. Loose sediment on the Moon’s surface increases the likelihood of shaking and landslides occurring. While more data is needed to fully understand the frequency and location of moonquakes, studies like this provide valuable insights for planning future Moon landings and lunar bases. Safety considerations are of utmost importance as NASA prepares for the Artemis mission, aiming to send astronauts back to the Moon. By carefully evaluating and selecting stable and secure locations for lunar outposts, the risks associated with geologically unstable zones can be minimized, ensuring the safety and success of future lunar exploration missions.