Planetary scientists have produced the first global map of small mare ridges on the Moon, adding new evidence that the lunar surface has been reshaped in geologically recent times by tectonic forces tied to the body’s long-term contraction. The findings, drawn from multiple peer-reviewed studies and institutional research programs, challenge the long-held assumption that the Moon is geologically dead. For space agencies planning crewed missions, the results carry potential safety implications: Apollo seismic records show the Moon still quakes, and recent analyses of landslides and boulder falls suggest some shaking can be strong enough to move surface material on slopes.
A Shrinking Moon and Its Telltale Ridges
The Moon is contracting because its interior continues to cool and shrink, a process that compresses the brittle crust and produces visible tectonic landforms on the surface. These features include wrinkle ridges and fault scarps that record millions of years of slow deformation, as described in LRO imagery that revealed previously unmapped tectonic structures. The contraction is not just ancient history. As NASA has put it, the Moon is still “quaking and shaking,” a description supported by Apollo-era seismic records and by orbital images of geologically young tectonic landforms that indicate the crust has continued to accommodate internal stresses.
A new study published in The Planetary Science Journal now adds a critical layer to that picture. Scientists compiled the first global catalog of small mare ridges, or SMRs, across the lunar maria, the dark volcanic plains visible from Earth. These low, sinuous ridges are interpreted as geologically young contractional tectonic landforms, meaning they likely formed relatively recently in the Moon’s history as the crust buckled under compressive stress. The catalog expands the known set of potential moonquake source structures, giving researchers and mission planners a more complete inventory of where tectonic strain is concentrated and where future fault slip might occur.
Apollo-Era Quakes Point to Active Faults
Seismometers left on the lunar surface by Apollo astronauts recorded shallow moonquakes decades ago, but only recently have scientists been able to connect those signals to specific geologic structures. A study in Nature Geoscience re-located several of those Apollo-era shallow moonquake epicenters and found that some fall close enough to young thrust-fault scarps to produce strong shaking at the surface. The timing of these quakes also aligns with tidal stress cycles, a pattern consistent with fault slip triggered when gravitational forces from Earth and the Sun flex the lunar crust at predictable intervals and push already stressed faults toward failure.
That tidal connection matters because it implies a degree of predictability in lunar seismicity, but also a persistent, recurring source of hazard. The study concluded that the Moon is tectonically active, not in the dramatic plate-tectonic sense familiar on Earth, but through steady contraction that loads faults until they rupture. For future surface operations, this means that seismic risk is not hypothetical or confined to the deep past. It is a present condition, recorded in instrument data and written into the geology of young fault systems that cut across terrain where astronauts may one day work, drive rovers, and build infrastructure that must withstand repeated shaking over long-duration missions.
Landslides and Boulder Falls Near Apollo 17
Some of the most vivid evidence of recent tectonic shaking comes from the Taurus-Littrow valley, where Apollo 17 astronauts landed in 1972. A study published in Science Advances examined boulder falls and landslides near the Apollo 17 site and used them to infer ground acceleration and quake magnitude. The researchers identified the Lee-Lincoln thrust fault as a likely source of the shaking that dislodged those boulders, a conclusion also highlighted in a Smithsonian news release that described how numerical models linked fault slip to observed blocks that had rolled down slopes and left fresh tracks in high-resolution imagery.
This paleoseismic approach, reading quake history from displaced rocks rather than from seismometer traces, fills a gap left by the limited lifespan of Apollo instruments. It also demonstrates that tectonic shaking on the Moon is not just detectable in data; it physically moves material across the surface in ways that can threaten hardware and habitats. The evidence points to recent and ongoing tectonic shaking, which means that landing sites near known fault structures could face real ground-motion risks during extended surface stays. For planners, the Taurus-Littrow case study serves as a template for assessing whether candidate bases sit within reach of active faults capable of triggering landslides on nearby slopes.
Landslides in the Past 15 Years Suggest Active Seismic Zones
Perhaps the strongest argument against treating lunar tectonics as a relic of the distant past comes from evidence of surface changes detected in image pairs spanning roughly the last 15 years. Research published in National Science Review documented very recent lunar surface mass wasting and concluded that the observed changes are more consistent with endogenic seismic activity, meaning moonquakes, than with meteorite impacts. The team compared pairs of images taken years apart and identified new landslides and disturbed regolith, then used statistical tests to show that the pattern of changes is inconsistent with a purely impact-driven process, especially in regions where no fresh craters are seen nearby.
This finding challenges a common assumption in lunar science: that most fresh surface disturbances are caused by the constant rain of small impactors hitting the airless Moon. Instead, the clustering pattern points to internal forces as the primary driver of recent change. If seismic activity is heterogeneous, then some areas of the Moon are significantly more prone to shaking than others, creating a patchwork of higher and lower risk across the surface. For Artemis-era exploration, that heterogeneity suggests that site selection should incorporate not only illumination, resources, and communications, but also proximity to zones where recent landslides betray ongoing moonquake activity that could endanger surface operations.
Implications for Future Lunar Exploration
Collectively, these studies recast the Moon as an active, evolving world whose surface continues to respond to internal and external forces. The global mapping of small mare ridges, the re-analysis of Apollo-era quakes, the reconstruction of boulder falls near Apollo 17, and the identification of landslides within the last decade and a half all converge on the same conclusion: lunar tectonism is recent, spatially organized, and strong enough to reshape the landscape. For scientists, this opens up new questions about how a small, airless body can retain enough internal heat and stress to keep faults active billions of years after formation, and how those processes compare to tectonic activity on other rocky worlds.
For mission planners, the practical message is equally clear. Infrastructure on the Moon will have to be designed for a seismically active environment, with attention to anchoring habitats, securing surface hardware, and avoiding steep slopes near active faults where landslides could be triggered. Across this growing body of peer-reviewed work, the emerging takeaway is that lunar quakes are not a curiosity but a design constraint. Understanding where and when the Moon shakes will be central to building a sustainable human presence on its surface, turning tectonic hazards into manageable engineering challenges rather than mission-ending surprises.
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*This article was researched with the help of AI, with human editors creating the final content.
