Earth is spinning faster than usual. August 5 may be one of the shortest days on record

The Earth seems to be in a bit of a rush, and scientists aren’t sure why. Tuesday, August 5, 2025, is expected to be one of the shortest days in recorded history, as our planet’s rotation speeds up ever so slightly. According to CNETthe Earth may complete its spin around 1.25 to 1.51 milliseconds faster than usual. While that sliver of time is too tiny for humans to feel, it’s certainly caught the attention of scientists and timekeepers around the world.

This isn’t the first time the Earth has picked up speed in recent years. Similar brief surges were recorded earlier this summer on July 10 and July 22. If Tuesday’s acceleration reaches the upper predicted limit of 1.51 milliseconds, August 5 would rank as the third-shortest day ever observed, just behind June 30, 2022 (1.59 ms shorter), and July 5, 2024 (1.66 ms shorter), reported Time and Date.

Time experts at the International Earth Rotation and Reference Systems Service, along with the US Naval Observatory, have updated their initial estimate of a 1.51 millisecond reduction down to 1.25 milliseconds. For context, a full rotation of the Earth normally takes 86,400 seconds, so a few milliseconds won’t impact daily life, even though it’s scientifically significant.

What’s causing this strange speed-up?

There’s no single clear answer yet, but one prevailing theory points to the Moon. The position of the Moon relative to Earth plays a subtle role in our planet’s rotation. When the Moon is positioned farther north or south of the equator, it can slightly affect how quickly Earth spins. On August 5, the Moon will be positioned significantly south of the equator, potentially nudging the Earth into this rapid rotation mode.

This change is expected to be temporary, and doesn’t have long-term consequences on Earth’s orbit, at least not yet.

A cosmic mystery in motion

Historically, Earth’s rotation has been gradually slowing down. Roughly 245 million years ago, during the time of the dinosaurs, a day was about 1.5 hours shorter. Most of this deceleration is caused by the Moon’s gravitational pull affecting Earth’s oceans.

However, since the 1970s, when precise timekeeping began, scientists have noticed an unexpected pattern: Earth occasionally speeds up. And the reasons remain largely unexplained.

One potential explanation, cited in a 2023 Nature study and highlighted by CNET, is that Earth’s core might be slowing down; ironically, this could cause the outer layers of the planet to rotate faster. But that theory, while compelling, hasn’t yet been confirmed.

For now, Earth’s fast-forward spin remains one of the more intriguing puzzles for planetary scientists. And while we won’t notice the milliseconds whizzing by, August 5 will quietly make history—as one of the briefest days we’ve ever known.