Earth's rotation has been accelerating since 2020, leading to the shortest days on record. Last year, the shortest day was on July 5, and Earth is expected to approach this record again in July and August this year.

Key Facts

Earth normally takes 24 hours to complete one rotation, equal to 86,400 seconds. However, since 2020, Earth has been rotating faster, resulting in days as short as 1.66 milliseconds less than 86,400 seconds. The exact dates for the shortest days this year are predicted to be around July 9, July 22, and August 5. The moon's position plays a role in this phenomenon, affecting Earth's rotation speed due to gravitational pull.

Reasons for Accelerated Rotation

Scientists are uncertain about the exact reasons behind Earth's faster rotation. Possible factors include changes in Earth's core and mantle movements, mass redistribution from melting ice sheets, ocean currents, air movements, and the Chandler wobble, which involves shifts in Earth's poles.

Negative Leap Seconds

Traditionally, leap seconds have been added to match atomic time with Earth's rotation. However, with Earth now spinning faster, negative leap seconds are being considered instead of adding time. This adjustment is crucial for maintaining global time accuracy, especially for systems like GPS, satellite navigation, financial transactions, and network synchronization.

Significance

While the acceleration of Earth's rotation may seem insignificant, it has significant implications for timekeeping accuracy worldwide. Ensuring alignment between Earth time and atomic time is essential for various technological systems and networks that rely on precise time measurements.

Source: Forbes