Moonquakes Threaten Future Manned Missions and Outposts on Shrinking Moon
In a recent study, scientists have discovered that the Moon’s shrinking size is causing significant seismic activity, known as “moonquakes,” which could potentially jeopardize future manned missions and the establishment of outposts. This finding has raised concerns about the suitability of a potential site near the lunar south pole, which was earmarked for NASA’s future mission to the Moon.
The region near the lunar south pole has gained international attention after India’s Chandrayaan-3 lander successfully touched down there in August. One of the primary objectives of the Indian mission is to locate water sources, as scientists believe that ice could be found in the large craters in the permanently shadowed south polar region. NASA has also selected an area in this region, called the de Gerlache Rim II, as a candidate landing spot for its Artemis 3 mission, scheduled for late 2026.
The study, conducted using data from NASA’s Lunar Reconnaissance Orbiter (LRO), revealed that the proposed landing site near the lunar south pole has experienced significant seismic events. These moonquakes, recorded by seismometers left behind by previous Apollo astronauts, could pose potential threats to personnel on future manned missions or living in new settlements. The tremors could cause landslides or create new faultlines, compromising the stability of outposts.
“Our modeling 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,” explained Thomas R Watters, a senior scientist emeritus at the National Air and Space Museum’s Center for Earth and Planetary Studies and the lead author of the study. He emphasized that when planning the location and stability of permanent outposts on the Moon, it is crucial to consider the global distribution of young thrust faults and their potential to be active, as well as the possibility of new thrust faults forming due to ongoing global contraction.
The Moon’s shrinking size is attributed to its still-hot and molten core. As it cools, the Moon contracts and becomes smaller. Over the last hundreds of millions of years, the Moon’s circumference has decreased by approximately 50 meters due to tidal forces exerted by Earth. This cooling process leads to the formation of faultlines, or “thrust faults,” on the Moon’s brittle surface, resulting in moonquakes. Thrust faults occur when a section of older crust pushes up over its younger neighbor, creating small cliff-like steps called “scarps.”
A previous study conducted in 2019 used analytical modeling and data from Apollo seismometers to identify the epicenters of eight moonquakes. This study provided the first evidence that these faults are still active and capable of producing moonquakes as the Moon continues to cool and shrink. Some of these quakes can reach a magnitude of around five on the Richter scale.
The discovery of ongoing seismic activity on the Moon raises important considerations for future manned missions and the establishment of outposts. Scientists and space agencies must carefully assess the stability and safety of potential landing sites, taking into account the presence of active thrust faults and the potential for new faultlines to form. While these challenges may complicate plans for lunar exploration, they also highlight the importance of thorough research and preparation to ensure the success and safety of future missions.