Feb 12, 2024
The moon is shrinking a tiny bit. It's not enough to noticeably affect our view or the shifting of the tides, but it could pose potential dangers for humans who might choose one day to live there.
That shrinkage is triggering strong moonquakes that could cause problems for long-term missions to the moon. It amounts to just 150 feet in circumference over hundreds of millions of years.
"There's a lot of activity that's going on in the moon," study leader Tom Watters told USA Today. "It's just something that we have to keep in mind when we're planning, especially, long-term outposts on the moon."
The study was published in the journal Planetary Science. It found that the moon’s shrinking is caused by the cooling of its molten core. And it's creating surface ridges called “thrust faults.” Thousands of these ridges have been found across the moon. Most ridges are tens of yards high. They've been shown to be sources of seismic activity. When they shake, they can trigger landslides, experts say.
Quakes that might seem minor on Earth could be far more intense on the moon. That's because of the moon’s low gravity. The quakes could last hours instead of minutes, experts say. Seismometers left by Apollo astronauts more than fifty years ago made it possible to measure quakes during the 1970s. The equipment measured quakes as strong as magnitude 5. The most intense quakes have happened near the south pole. That's where NASA hopes to land astronauts within the next few years.
Watters told USA Today that the short-term Artemis human missions aren’t likely to be affected. But he did note the chances that a moonquake will disrupt a mission increase if humans put a long-term structure on the moon.
Photo from Unsplash courtesy of Alexander Andrews.
Reflect: How do you think living on the moon might pose unique challenges for humans?
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