The moon is shrinking, study shows: How it could impact NASA missions

(NEXSTAR) — The moon has graced our skies for eons, sometimes appearing as small as a fingernail, other times as a supermoon. But, research shows the moon is in fact shrinking, and missions to explore a fascinating region of it could be at risk.

In a paper published in The Planetary Science Journal last month, researchers explained that they’ve found the moon’s south polar region “has experienced the effects of the shrinking moon,” a press release from the Smithsonian says.

We’ve known the moon is shrinking for some time. In 2019, NASA reported the moon had lost about 150 feet over the last several hundred million years due to interior cooling. The moon, like Earth, experiences quakes (known as moonquakes) and faults, as its interior cools gradually and shrinks, NASA explains.

This new research helps scientists understand how those moonquakes and faults the moon is experiencing could impact lunar missions.

“Our modeling suggests that shallow moonquakes capable of producing strong ground shaking in the south polar region are possible from slip events on existing faults or the formation of new thrust faults,” Tom Watters of the Smithsonian Institution and lead author of the paper said in a news release. “The global distribution of young thrust faults, their potential to be active, and the potential to form new thrust faults from ongoing global contraction should be considered when planning the location and stability of permanent outposts on the moon.”

Some of those moonquakes and faults have been found near and within areas NASA says it has considered as possible landing spots for Artemis III, the first crewed lunar landing by the U.S. in more than 50 years.

Scientists are hoping to explore the moon’s south pole because it is believed the craters there may hold frozen water that could aid future missions.

India became the first country to land a spacecraft near the pole last year. Its unmanned rover was looking for signs of that frozen water, which could provide future astronauts with drinking water or a way to make rocket fuel. Indian scientists said that the next step is a manned lunar mission.

According to the researchers, some areas of the south pole are susceptible to landslides, which could make manned missions to the region challenging.

Despite the concerns over the lunar surface and its stability through moonquakes and faults, there is no immediate impact on the planning to land Artemis III near the south pole, Renee Weber, a NASA planetary scientist and co-author of the study, told CNN. She explained that not only are moonquakes difficult to predict (like earthquakes), but that “strong shallow moonquakes are infrequent and pose a low risk to short-term missions on the lunar surface.”

The study could, however, impact any plans humans have to be present on the moon long-term.

Does a shrinking moon impact Earth?

If you don’t have any plans to visit the moon, should you be concerned? The moon does influence our tides and can provide a fun celestial show (like this summer’s solar eclipse). Will those events be impacted?

Fortunately, the shrinking is happening at a very, very slow pace: just 150 feet over the last few hundred million years, NASA reports. That means you probably won’t notice any change in your lifetime.

Plus, the moon’s mass remains the same, Nicholas Schmerr, a co-author of the study from the University of Maryland, told USA Today, so tides likely won’t be affected “in any substantial way.”

The Associated Press contributed to this report.