Future Lunar Bases Face Challenge After Study Shows Moon Still Tectonically Active

NASA plans to build permanent bases on the Moon within the next decade, but most astronauts probably weren’t worrying about potential seismic activity. New research indicates parts of the lunar surface may still be tectonically active, potentially adding yet another factor for cosmic engineers to contend with as humanity looks toward a future amongst the stars.

Scientists have mapped 2,634 fault segments scattered across the Moon’s dark volcanic plains, many of which could act as sources of shallow moonquakes. For the first time, mission planners have detailed maps of where these faults sit, information that will be crucial for assessing seismic hazards at future landing sites.

When Apollo astronauts left seismometers on the lunar surface in the early 1970s, the instruments recorded thousands of shallow moonquakes over the next eight years. The problem was that researchers couldn’t figure out where those quakes originated or predict where future ones would strike. A team from the Smithsonian Institution and NASA has now identified thousands of fault lines whose shallow depths are consistent with the range of Apollo-detected moonquakes, many of which formed relatively recently in geological terms.

Why Moonquakes Matter for Lunar Bases

Moonquakes pose unique challenges because the Moon lacks an atmosphere and water to dampen seismic waves. Previous Apollo data showed that lunar seismic events can shake the surface for extended periods. Even moderate moonquakes could pose risks to habitat seals, solar panels, communication towers, or trigger landslides in the loose lunar soil that blankets the surface.

The newly mapped faults appear as small ridges, most barely taller than a 10-story building, wrinkling the ancient lava flows that fill the Moon’s dark basins. Lead author C.A. Nypaver and colleagues used high-resolution cameras aboard NASA’s Lunar Reconnaissance Orbiter to spot these features. Age estimates suggest many formed within the past few hundred million years, with some as recent as 50 million years ago. Many show minimal weathering from meteorite impacts, suggesting geologically recent formation.

One region stands out in the analysis. Oceanus Procellarum (the Ocean of Storms, a massive lava plain visible from Earth) exhibits the highest modeled strain among the lunar maria. Other areas with notable fault populations include Mare Tranquillitatis (the Sea of Tranquility, where Apollo 11 landed) and Mare Serenitatis (the Sea of Serenity) to the north.

A Slowly Contracting Moon

As the Moon slowly cools over geological time, it contracts slightly. That process is enough to keep fracturing the brittle outer shell. When underground faults suddenly slip, the surface buckles upward into ridges while the ground shakes.

To figure out when these faults were active, researchers counted impact craters near the ridges. When a moonquake rattles the surface, the shaking can erase small nearby craters. By measuring which craters survived and which got erased, scientists determined these faults have been active within the past 310 million years, with an average age around 124 million years.

Computer modeling revealed the faults extend from about 30 to 200 meters below the surface, averaging around 100 meters deep. That’s notably shallower than similar faults in the Moon’s bright highlands. The shallow depth is consistent with the Apollo-era detection of shallow moonquakes.

Relevance for Future Lunar Exploration

These findings are relevant to upcoming exploration missions that aim to characterize lunar seismicity and assess potential hazards. Engineers designing future lunar habitats now have detailed maps showing which areas contain geologically young faults and where reinforced construction might be necessary. The maps also reveal areas with fewer identified faults.

Several planned seismic monitoring missions over the coming years will place instruments at key locations across the lunar surface. Instead of wondering where future moonquakes might originate, scientists can now monitor faults that have demonstrated geological activity in the relatively recent past.

The discovery also reveals that recent tectonic activity is not confined to the highlands but also occurs across the maria. Fault systems in the dark lava plains connect with fault systems in the bright highlands, indicating the entire Moon is responding to the same stresses from gradual contraction, tidal forces from Earth, and orbital changes.

We used to think the Moon finished its geological story billions of years ago when volcanic eruptions stopped filling its basins with lava. This research paints a more dynamic picture of a world still responding to slow cooling and external forces. For lunar science, that’s fascinating. For lunar habitation, it means mission planners now have the data they need to identify and monitor potential seismic hazards before anyone attempts to live there long-term.

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