The rate at which the Earth spins changed unusually on June 29, 2022. However, you may be excused for not even noticing because it probably had such a negligible effect on your life.
You did, in fact, extend your day by 1.59 milliseconds, as absurd as it may sound. We hope you made good use of it!
Yet why? As far as scientists can tell, our planet set a new record for the quickest time to complete one spin on that day, according to TimeAndDate.com. In other words, even though you “got” 24 hours on that day, you only “spent” 24 hours that were 1.59 milliseconds shorter.
What then? The day on Earth lasts exactly 24 hours. In actuality, no, not quite.
First, bear in mind that there are various “kinds” of days, depending on how you define the term.
The first is a 24-hour period known as a solar day, during which the Earth spins to keep the Sun in the same place in the sky. A sidereal day, on the other hand, is the length of time it takes for the Earth to complete one full rotation on its axis concerning distant stars. A sidereal day is measured in terms of 23 hours, 56 minutes, and 4.091 seconds.
We can determine the “speed” at which the Earth is rotating based on these known times. We just need to determine the circumference of our planet to do this. At the equator, the diameter of the Earth is around 24,901 miles (40,075 kilometers); dividing this by the number of hours in a day gives a spin speed of about 1,038 miles per hour (1670 kph).
But not every part of the globe revolves at the same speed. As you move north or south, the Earth’s circumference decreases, which causes the spin to slow down until it is at its slowest at both poles. Even so, it is still far slower than the 66,486.7 mph (107,000 kph) at which the Earth orbits the sun.
What about this “record-breaking” day, though? We must first learn a little bit about “leap seconds,” though.
The Earth’s rotation had been thought to be slowing down until a few years ago, according to many atomic clock readings since 1973.
The International Earth Rotation and Reference Systems Service (IERS) has even begun to occasionally add leap seconds to accommodate for the slower spin (it last happened on December 31, 2016).
Over longer periods, it may still be the case; the Earth’s rotation may still be generally slowing down.
After all, the Moon gradually slows down the Earth’s rotation. Because of the Moon’s gravitational pull and the Earth’s slightly elliptical orbit around the Sun, tides are created.
What is the speed of the Earth’s rotation?
However, atomic clocks have lately shown that the Earth’s rotation is accelerating quickly. It’s possible that a 50-year era of shorter days is already beginning.
The 28 shortest days since 1960 occurred in 2020, according to scientists. The tendency from the previous year was reversed in 2021, with the shortest day being longer than it was in 2020.
However, on June 29, 2022, our planet made its fastest rotation ever, and on July 26, 2022, it appears that a day had a shorter duration of 1.50 milliseconds.
On July 19, 2020, the Earth completed one revolution in 1.4602 milliseconds or less than 24 hours, shattering the previous mark.