video: Change detection conducted in the youngest, topographically steepest, and theoretically most unstable regions on the lunar surface revealed a large number of new landslides formed since 2009. Endogenic moonquakes rather than new impacts are the primary trigger, and the Imbrium basin may host an active seismic zone.
Credit: Zhouxuan XIAO
The research team, led by Professor Zhiyong Xiao from Sun Yat-sen University, along with colleagues from Fuzhou University and Shanghai Normal University, searched for short-term changes on the surface of the Moon using multi-temporal images obtained from 2009–2024. Their findings showed that most new landslides on the Moon were triggered by endogenic moonquakes, rather than by new impacts or thermal weathering of slope rocks, which could transform the knowledge of lunar surface processes and offer critical guidance for preventing potential geohazards to future lunar surface exploration and constructions.
For decades, scientists have sought to clarify what causes the widespread landslides on the Moon—a key process shaping its topography and an understudied potential geohazard for lunar surface exploration. Prevailing assumptions include both internal and external forces: endogenic moonquakes with various energy sources such as tides, cosmic impacts that induce near-field and far-field disturbances, and thermal weathering that possibly breakdown rocks due to the extreme diurnal temperature variations. However, limited observations of active landslides on the Moon left uncertainties about the activity level and potential triggers—a gap the new study aims to fill.
“Worldwide lunar exploration is accelerating, with plans for permanent research stations and deep-space outposts,” explains Dr. Xiao, lead author and researcher at Sun Yat-sen University’s Planetary Environmental and Astrobiological Research Laboratory. “Understanding today’s landslide activity and its drivers is essential for assessing geohazard risks to these future missions.”
To capture new landslides, the team targeted the Moon’s “least stable regions”—areas most prone to mass wasting, including young impact crater walls, fault-formed wrinkle ridges, and irregular mare patches that are potential sites of recent volcanic activity. New landslides in these areas would represent the current activity level on the Moon. They analyzed 562 pairs of high-resolution temporal images for 74 observation targets, evenly distributed at the Moon’s near and far sides to ensure results were representative of global conditions. With image resolution good enough to capture subtle surface changes, the researchers refined image analysis techniques to avoid false detection: they used precise co-registration to align before-and-after images and controlled for lighting differences.
In total, the team discovered 41 new landslides, a number comparable to that discovered by an earlier endeavour of global automatic search. The landslides are less than 1 km long, 100 m wide, and less than 1 meter thick, with volumes under 100,000 cubic meters—far smaller than large, ancient lunar landslides. They form on slopes of 24°–42°, near the angle of repose for lunar terrains, where loose material is most unstable. Boulders are not visible in the initiation zones of the landslides, and pervasive boulders on steep slopes did not yield landslides neither. Only 29% (12 of 41) of the new landslides were possibly linked to new impacts, as the new impacts occurred right in the initiation zones of the landslides. However, more than 2000 new impacts have been observed on the Moon, but only dozens of new landslides were discovered, suggesting that new impacts are not an efficient driver of current landslide on the Moon. The team also found that even larger recent impacts (up to 75 meters wide, among the biggest formed in the past 15 years) failed to trigger landslides on nearby steep slopes, confirming that new impacts have a low efficiency of triggering landslides.
The team found that 71% (29 of 41) of the new landslides had no connection to impacts or exposed rocks, leaving endogenic moonquakes as the only possible driver—consistent with the Moon’s interior containing molten portions. These landslides cluster in the eastern Imbrium Basin—a 3.92-billion-year-old impact basin, consistent with known zones of shallow moonquakes recorded by the Apollo seismometers, suggesting this area is a currently active lunar seismic zone.
By showing endogenic moonquakes dominate triggers of current lunar landslides, the research challenges traditional models and highlights the need to prioritize internal lunar activity in studies of its surface evolution. The spatial distribution of active landslides may serve as a “proxy” for subsurface seismic activity—helping scientists map hidden lunar earthquake zones without deploying seismometers everywhere. While the small, localized landslides might pose limited overall geohazard risks, they warn against placing slope-proximal facilities in seismically active areas like the eastern Imbrium Basin. The basin also emerges as a priority site for deploying seismometers and thermal probes to study the Moon’s interior dynamics.
“Our work reminds us the Moon is not a static, dead world—besides abundant new impacts, landslide is active today,” says Dr. Xiao. “These insights bridge a gap between past lunar history and present-day processes, advancing both science and mission planning.”