Depositphotos
Physicists expect that this summer will be the shortest day in the history of observations.
According to astrophysicist Graham Jones, on July 9, 22, or August 5, the Earth is expected to make the fastest rotation on its own axis, breaking last year’s record. Changes in day length are influenced by the orbit of the Moon. The Earth is rotating faster, when the moon is far away north or south of the equator. On three projected dates in 2025, the Moon will be at the maximum distance from the equator.
The Earth makes a complete rotation around its own axis in 86 thousand 400 seconds with an error of about 1 millisecond. One millisecond is 0.001 seconds. For comparison, an eye blink lasts about 100 milliseconds.
Scientists measure subtle changes in the speed of our planet’s rotation using atomic clocks. Until 2020, the shortest recorded day length was1.05 ms. That is, the Earth made one rotation 1.05 milliseconds faster than the usual 86 thousand 400 seconds. Since then, our planet has annually set a record for rotation speed by about half a millisecond. The shortest day of all was -1.66 ms on July 5, 2024.
Scientists do not know the exact reasons for the acceleration of the Earth’s rotation. Changes in the speed of our planet’s rotation depend on many complex factors, including, complex movement of the core and — from the oceans and atmosphere. Most scientists believe it is something inside the Earth. Ocean and atmospheric models do not explain this huge acceleration.
The Moon has actually been slowing down the Earth’s rotation for billions of years. About 4.5 billion years ago, the Earth’s day lasted from 3 to 6 hours. The tidal forces caused by the Moon are one of the factors that make the Earth lose momentum. The Moon continuously absorbs part of the Earth’s rotational energy.
Currently, it takes the Moon about 27 days to make one revolution around the Earth. Once upon a time, the speed of the Moon’s orbital period and Earth rotation are synchronized, which means that the Moon will be visible from only one half of the planet at all times. However, researchers predict that this will happen no earlier than in 50 billion years. By then, neither the Earth nor the Moon may exist.
Source: Time and Date