The moon is not this benign place where nothing is happening.
For millions of years, the moon has been quietly contracting — its cooling core pulling the surface inward, leaving behind faults and fractures that still shift and shudder. Now, as humanity prepares to return to the lunar south pole, a NASA-funded study reminds us that the world we are rushing toward is not the silent, frozen relic we imagined, but a place still in the slow process of becoming. The ambitions of nations — American, Chinese, Indian — converge on a region rich with water ice and scientific promise, but also with a geological restlessness that will demand humility and careful planning from those who wish to stay.
- The moon has shrunk 150 feet in circumference over millions of years, and the resulting faults near the lunar south pole are still actively triggering moonquakes — some lasting hours, some strong enough to topple a person in the moon's low gravity.
- The south pole has become the most contested destination in space exploration, with NASA's Artemis III, China, and India all racing to establish footholds in a region prized for its water ice deposits.
- A magnitude 5.0 moonquake — the strongest recorded near the south pole — was detected by Apollo-era seismometers, and new research has finally linked those ancient tremors to a network of young, active surface faults.
- Short-term missions like Artemis III face minimal seismic risk, but scientists and engineers warn that permanent lunar bases will require rigorous seismic hazard mapping before anyone commits to a location near active fault lines.
- Researchers disagree on the precise origin of the shallow moonquakes, but converge on a shared conclusion: the moon is geologically alive, and future missions must treat its restlessness as a serious engineering and safety variable.
The moon is shrinking. Over millions of years, its cooling interior has been contracting, wrinkling the surface into faults and fractures that still rupture under stress — triggering moonquakes that can last for hours and send landslides cascading across the terrain. A new NASA-funded study, published in The Planetary Science Journal in late January, has connected those tremors to a network of active young faults concentrated near the lunar south pole — the very region humanity is preparing to visit.
The south pole has become the most coveted destination in space exploration. India landed there last year. Russia tried and failed. NASA has selected it as the target for Artemis III, which could return astronauts to the surface as soon as 2026. China is planning habitats there too. The lure is water ice — the raw material for long-term human presence beyond Earth. But the same geological forces that make the region scientifically valuable are also making it seismically unpredictable.
The strongest moonquake recorded near the south pole measured magnitude 5.0, captured by seismometers left by Apollo astronauts more than fifty years ago. On the moon, where gravity is one-sixth that of Earth, such a quake would be violent enough to knock a person off their feet. Thomas Watters, the senior scientist who led the research, was direct: the moon is not the geologically dead world most people picture. It is still settling into its smaller shape, still releasing the heat of its formation.
For Artemis III — a mission lasting roughly a week — the risk is low. Strong shallow moonquakes are infrequent, and NASA's thirteen candidate landing sites were chosen with safety and terrain in mind. This study changes little about that near-term planning. But the calculus shifts dramatically for permanent bases, where people might live for months or years. Proximity to active faults would then become a critical site-selection factor — one that future missions, and the seismic data they gather, will help resolve.
Scientists disagree on some details — including how deep the quakes originate — but agree on the essential point: the moon is not a stable platform. It is a world still in motion, and those who intend to stay will need to learn its rhythms before they build.
The moon is cracking. Not visibly, not catastrophically, but steadily—the way a grape shrivels into a raisin as it loses moisture. Over millions of years, the lunar core has been cooling and contracting, and that slow collapse is reshaping the surface in ways that matter now, because humans are about to land there.
The lunar south pole has become the hottest real estate in space exploration. India's Chandrayaan-3 touched down there last year in a historic soft landing. Russia tried and failed. NASA has chosen the region as the target for Artemis III, which could return astronauts to the moon as soon as 2026. China is planning habitats there too. The draw is simple: water ice, the foundation for long-term human presence beyond Earth. But a new study funded by NASA is complicating the picture. The very geological forces that make the south pole scientifically valuable are also making it seismically restless.
As the moon's interior cools, its surface develops wrinkles—faults and fractures that rupture under stress. These ruptures trigger moonquakes. Some last for hours. Some trigger landslides. The strongest recorded moonquake near the south pole registered magnitude 5.0, detected by seismometers left behind by Apollo astronauts more than fifty years ago. On Earth, that would be moderate. On the moon, where gravity is one-sixth as strong, the shaking would be violent enough to knock a person off their feet. Thomas Watters, the senior scientist emeritus at the National Air and Space Museum who led the research, described the moon not as the geologically dead place most people imagine, but as an active world where young faults are still moving. "The moon is not this benign place where nothing is happening," he said.
The study, published in The Planetary Science Journal on January 25, used data from NASA's Lunar Reconnaissance Orbiter, which has been mapping the moon since 2009, to connect those ancient Apollo seismic readings to a network of faults in the south pole region. For decades, scientists knew shallow moonquakes were occurring there but couldn't pinpoint the source. The detective work pointed to these young, active faults as the culprit. The moon has shrunk roughly 150 feet in circumference over the last few million years—a significant contraction in geological time, though too small to affect Earth's tides or climate.
The immediate risk to Artemis III is low. NASA planetary scientist Renee Weber explained that strong shallow moonquakes are infrequent, and predicting them is as difficult as predicting earthquakes on Earth. The Artemis mission will land two astronauts for about a week. The odds of a major quake striking during that brief window are small. The agency has identified thirteen candidate landing sites near the south pole, selected based on safety, scientific value, launch windows, and terrain conditions. This study won't change that selection process.
But the longer humans stay on the moon, the calculus shifts. If NASA and other space agencies build permanent bases—habitats where people live for months or years—then proximity to active faults becomes a serious site-selection criterion. Yosio Nakamura, a geophysics professor emeritus at the University of Texas who helped analyze the original Apollo seismic data, disagreed with Watters about what causes the shallow quakes, arguing the data suggests they originate deeper underground. But he agreed on the core point: moonquakes pose a potential threat to future missions, and more data is needed. Allen Husker, a geophysicist at Caltech, noted that by the time a permanent moon base exists, multiple future missions will have provided far better understanding of the seismic hazard. Jeffrey Andrews-Hanna, a planetary scientist at the University of Arizona, reframed moonquakes as scientific tools—"flashlights in the lunar interior" that reveal the moon's structure and ongoing activity.
So the south pole remains the destination. The water ice is still there. The science is still compelling. But the moon, it turns out, is not a stable platform. It is alive in its own slow way, still adjusting to the loss of its internal heat, still settling into its smaller shape. Future lunar explorers will need to account for that restlessness.
Citações Notáveis
The moon is not this benign place where nothing is happening. These faults are very young and things are happening.— Thomas R. Watters, senior scientist emeritus, National Air and Space Museum
Strong shallow moonquakes are infrequent and pose a low risk to short-term missions on the lunar surface.— Renee Weber, NASA planetary scientist
A Conversa do Hearth Outra perspectiva sobre a história
Why does the moon's core cooling matter now? It's been cooling for billions of years.
True, but the effects are accelerating in ways we can measure. The surface is young and active—landslides have occurred just in the time the Lunar Reconnaissance Orbiter has been watching. And we're about to put people there.
So the moonquakes themselves—are they getting stronger?
Not necessarily stronger. But they're happening, and we're only now connecting them to the faults causing them. For fifty years we had seismic data from Apollo but no explanation. Now we know what's making the ground shake.
A magnitude 5.0 quake doesn't sound that bad.
On Earth, with strong gravity holding you down, it's manageable. On the moon, you weigh one-sixth as much. That same shaking would throw you off your feet. In a spacesuit, tethered to equipment, that's dangerous.
Does this mean Artemis shouldn't land there?
No. The risk to a week-long mission is low—strong quakes are rare. But if we're building a base where people live for months, we need to know where the faults are and how often they slip.
What's the real unknown here?
We still don't fully understand what triggers the shallow moonquakes. The study points to surface faults, but other researchers think the source is deeper. Either way, we need more data before we commit to permanent settlement.