The Earth spun a little faster recently, but scientists aren’t ‘gravely concerned’

Twenty-four hours is hardly enough time in a day, but now the internet says the days are getting shorter! Are scientists worried? Should you be worried?

Several posts on Facebook, mostly posted Aug. 7 on meme pages, have stated that the Earth "just started spinning faster and scientists are gravely concerned." 

The claim was flagged as part of Facebook’s efforts to combat false news and misinformation on its News Feed. (Read more about our partnership with Facebook.)

We wondered if either part of the statement was true. 

First: Yes, on June 29, 2022, the official length of day was 1.59 milliseconds shorter than 24 hours. That’s the fastest the Earth has ever spun since we started keeping track with precision of atomic clocks.

However, that’s "nothing out of the ordinary," according to a press release from NASA. According to Wolfgang Dick, a spokesman for the International Earth Rotation and Reference Systems Service, it’s inaccurate to suggest there was anything sudden about this change. "(T)his fluctuation is quite normal," wrote Dick to PolitiFact in an email. 

The International Earth Rotation and Systems Service, based in Frankfurt, Germany, maintains global time and reference frame standards.

Several things can affect the rotation of the Earth and, thus, its spin speed, including a slight wobble of the Earth on its axis, called the Chandler wobble. The moon stabilizes the Earth’s wobble to some extent. According to Forbes, possible reasons that the Earth spun faster in June include seismic activity, changes in the Earth’s core, and polar ice caps melting. 

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Second: Are scientists "gravely concerned?" 

We contacted Leonid Zotov, an associate professor at the National Research University Higher School of Economics in Moscow and senior researcher at Sternberg Astronomical Institute, Lomonosov Moscow State University, who recently presented his paper on Earth’s changing rotation. 

"The changes in Earth's rotation are quite small, at the level of milliseconds," he told us. "The(y) cannot make any harm." He also noted that the Earth changes the speed at which it spins regularly over the course of a year, going slightly faster in the summer, with no detrimental effects. 

Still, Zotov describes these changes as "really interesting." "There are correlations with climate anomalies," he wrote. "My personal belie(f) is that this year's drafts and such events as La Niña in (the) central Pacific could be related to acceleration in our planet's rotation." 

With enough sped-up days, we might need to add a "negative leap second." As a leap day amounts to adding a day to a year, a negative leap second would subtract one second from the time. But changing official calendars can be complicated and isn’t always harmless. For example, a leap second added in 2012 crashed several websites, including Reddit. 

It’s true that the Earth spun slightly faster on June 29, 2022 — 1.59 milliseconds faster than usual. Facebook posts suggested this means Earth is now continuously spinning faster, at a pace so significant that scientists are worried. 

But 1.59 milliseconds isn’t significantly outside of expectations. There is no evidence to suggest this should pose a danger to anyone on Earth, so scientists are not "gravely concerned."

We rate these claims Half True.