Why was June 29 the shortest day on Earth since 1960?

Midnight on June 29 came 1.59 milliseconds earlier than expected, a record on Earth for more than 6 decades.


June 29 was the shortest day on Earth since 1960, when scientists began to accurately measure the planet’s rotation using atomic clocks.

According to the researchers, that day was 1.59 milliseconds shorter than the 86,400 seconds of the day.

Why was the shortest day on Earth?

According to science, the Earth “wobbles” on its axis (not being perfectly spherical) and the trend ensures that its rotation speed is accelerating.

This behavior occurs because the planet has a bulge at the equator, while the poles are slightly flattened, which means that the Earth is slightly elliptical.

Other factors can also interfere with the spin, including ocean tides and the Moon’s gravity.

Chandler’s wobble?

Math professor Leonid Zotov thinks the Earth may be spinning faster due to a periodic motion called “Chandler wobble,” he tells Insider.

The wobble was first detected in the late 1880s, when astronomer Seth Carlo Chandler noticed the poles moving over a period of 14 months. This wobble began to slow in the early 2000s, reaching record lows since 2017, according to the Telegraph .

And between 2017 and 2020, “it disappeared,” Zotov told timeanddate.com. He will now present this theory to the Asia-Oceania Society of Geosciences.