The Moon Is Shrinking, Again — Scientists Warn Lunar Bases May Pay the Price

From Earth, the Moon has always appeared serene as a pale disk that hangs over rooftops and power lines, but as scientists get closer, the moon appears less motionless. According to new research, our satellite is still shrinking, with its crust cracking and wrinkling as the interior gradually cools. Even though it’s a gradual process that takes millions of years to measure, the effects seem immediate now that people are getting ready to go back and perhaps stay.

The lunar plains look like dried paint from orbit, smooth and inert. They tell a different story up close. The total number of ridges in the dark volcanic maria has risen to thousands after scientists mapped over a thousand previously undiscovered ridges. These low, sinuous wrinkles, some of which are young by lunar standards, show how the Moon’s crust is being compressed as it gets smaller. Like a drying apple puckering beneath its own skin, it tightens gradually.

The size of the recently discovered features suggests a global system of compression, even though scientists have long known the Moon was contracting. Ridges in the plains and fault lines in the highlands combine to form an ongoing network. Each ridge indicates crustal stress. Movement is suggested by every stress point. Additionally, movement—even slight movement—increases the likelihood of earthquakes.

It’s hard not to picture future astronauts stepping onto ground that looks frozen in time yet occasionally shudders beneath them. Decades ago, Apollo seismometers captured shallow moonquakes, including a powerful tremor close to the south polar region, which is now the target of crewed landings. Like a struck bell, those vibrations probably reverberated through the arid lunar crust for a much longer period of time than earthquakes do on Earth.

Extremes in temperature, radiation, and dust are already concerns for mission planners. Seismic stability is now being added to the list. Loose regolith, which are powdery fragments formed by impacts over billions of years, is layered on the lunar surface. That material slides easily when shaking starts, causing landslides along steep slopes and crater walls. Shackleton Crater, prized for its ice deposits, may also harbor unstable edges. Risk and opportunity are adjacent.

It seems as though the risks associated with the Moon are compelling a more modest approach to exploration. On basalt plains, engineers once envisioned stable habitats and smooth landing zones. These days, they discuss flexible structural design, fault mapping, and terrain modeling with more caution. Structures might have to absorb seismic energy. Landing locations might change. Routes for rovers may also change.

The timing is remarkable. In order to prepare for a longer-term stay later in the decade, NASA‘s Artemis program seeks to send humans back to the Moon in the coming years. Private space companies, legislators, and investors have started to view lunar infrastructure as a given. However, the Moon itself seems to be reminding planners that it is still a world in motion, albeit one that is quiet.

The contraction is natural and a byproduct of the Moon’s thermal evolution, according to scientists. Its surface retains signs of stress over incredibly long periods of time because neither plate tectonics nor weather can remove scars. Some ridges are surprisingly young in geological terms. That young person raises the possibility that tectonic activity is still occurring, which could be addressed by future missions.

As this is happening, the way people view the Moon is subtly changing. It is no longer just a place to go or a test site. It defies the tidy projections of human planning and feels more like a place with its own rhythms and dangers. The assumption that technology can overcome the environment is common in exploration narratives. The Moon’s silent contraction in the shadows alludes to compromise rather than conquest.

It’s still unclear whether lunar quakes will pose serious threats to future bases, or simply engineering challenges that can be mitigated with thoughtful design. However, the identification of extensive fault systems and ridges makes site selection and construction techniques even more urgent. Every new map shows tension beneath the surface in addition to the terrain.

For the time being, the Moon is unconcerned with human timelines and keeps tightening, millimeter by millimeter, ridge by ridge. Stresses are building up and waiting to be released somewhere in those quiet plains, beneath fine dust that hasn’t been disturbed in ages.