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Scientists puzzled as Earth’s rotation unexpectedly speeds up with record-breaking short days expected soon
Imagine waking up one morning to find out that your day just got shorter—but not because you’re running late. Scientists say Earth’s rotation is literally speeding up, and we could be in for the shortest day ever recorded in just a few weeks.
According to astrophysicist Graham Jones from the University of London, Earth might shave off over a millisecond from a typical day this summer—on July 9, July 22, or August 5. The shortest day could be 1.51 milliseconds quicker than the usual 24-hour cycle. It may not sound like much, but when it comes to planetary motion, even a sliver of a millisecond matters—a lot.
What’s Causing the Rush?
No one’s quite sure why our planet is suddenly in a hurry. Leonid Zotov, a scientist from Moscow State University, admitted, “Nobody expected this. The cause of the acceleration is not explained.” That’s right—Earth’s spin-up has left experts scratching their heads.
Up until a few years ago, Earth was actually slowing down. Thanks to the moon’s gravitational tug, the length of our days has gradually stretched over millions of years. But something strange began happening in 2020. Earth started spinning a bit faster, breaking records for the shortest days ever tracked.
The current record-holder is July 5, 2024, when the planet completed its rotation 1.66 milliseconds faster than normal. Now, scientists warn that a new record could be set very soon.
The Usual Suspects: What’s Speeding Us Up?
Researchers are exploring all possible culprits. Earth’s spin isn’t perfectly steady—it naturally fluctuates due to a mix of forces, including:
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Molten movement in Earth’s core – Like a spinning figure skater pulling in their arms, swirling metal deep inside the planet can change its speed.
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Shifting ocean currents and high-altitude winds – Mass movement from water and air can subtly affect the Earth’s rotation.
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Melting glaciers – As polar ice melts, it redistributes Earth’s mass, which may impact spin speed.
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Tectonic activity – Earthquakes can even create temporary bumps or dips in the planet’s rotation.
Still, these known factors don’t fully explain the recent uptick in speed, leading to the mystery that continues to baffle scientists.
Why Should You Care About a Millisecond?
It turns out that even a teeny tiny change in Earth’s rotation can have big ripple effects.
Modern technologies—from GPS and satellite systems to internet time servers and global financial transactions—are all synced with what’s called Coordinated Universal Time (UTC). This timekeeping standard is based on atomic clocks, which measure time down to billionths of a second.
When Earth spins slower, we occasionally add a leap second to UTC to stay in sync. But if the current acceleration keeps up, we might need to do the opposite—subtract a second. That’s called a negative leap second, and it’s never been done before. Introducing one could be tricky, potentially throwing off systems that depend on ultra-precise timekeeping.
What’s Next?
Scientists are closely monitoring upcoming days, especially in July and early August, to see if we hit the new shortest day. Based on current models and recent data collected from the U.S. Naval Observatory and international Earth rotation services, the planet’s pace seems to be picking up again after a brief slowdown in 2023.
So, while you won’t feel any faster on your morning jog, the Earth beneath your feet might be moving just a tiny bit quicker than it did yesterday.
For now, experts are digging deeper—literally—looking at everything from the molten core to the moon’s orbit to figure out what’s really going on inside our planet.
As Zotov put it, “Sooner or later, Earth will decelerate.” But until then, we’re spinning toward history—one millisecond at a time.
