Earth just had its shortest day on record, thanks to a ‘wobble’

The Earth experienced its shortest day this summer, thanks to an oscillation in its axis that allowed it to complete a single revolution in a fraction of a second in less than 24 hours.

June 29 was 1.59 milliseconds shorter than 86,400 seconds, or exactly 24 hours, according to

In recent decades, the Earth has been more likely to slow down, resulting in slightly longer days. But in recent years, this trend has reversed and the days are getting shorter and shorter.

If the Earth continues to accelerate, it could lead to the first-ever requirement to subtract a second from atomic clocks.

Earth is not perfect

It’s not uncommon for the Earth to wobble – the rotation we experience day and night doesn’t always occur exactly on the axis of its axis, the line between the North and South poles.

This is because it is not a precise sphere.

The planet has a bulge at the equator, while the poles are slightly flattened, which means Earth is slightly elliptical.

Other factors can also disrupt the rotation, including ocean tides and the Moon’s gravity.

The “Chandler wobble”

Mathematics professor Leonid Zotov thinks the Earth might be spinning faster because of a periodic motion called the “Chandler Oscillation.”

The wobble was first spotted in the late 1880s, when astronomer Seth Carlo Chandler noticed the poles wobbling over a 14-month period.

This oscillation began to slow in the early 2000s, reaching historic lows since 2017, for The Telegraph.

And between 2017 and 2020, “he disappeared,” Zotov told

Zotov is to present this hypothesis to the Asia Oceania Geosciences Society, according to It has not yet been peer reviewed.

The oscillations of the Earth do not change much in everyday life. But they’re important to keep track of, so the atomic clock can stay accurate to precisely coordinate GPS and Earth observation satellites.

This article was originally published by Business Insider.

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