Scientists are raising alarm bells as Earth’s rotation speeds up unexpectedly, leading to what may soon be the shortest day in recorded history. Astrophysicist Graham Jones from the University of London has indicated that Earth’s rotation could noticeably accelerate on one of three upcoming dates this summer—July 9, July 22, or August 5. During these dates, the planet’s day is predicted to shorten by 1.30, 1.38, or 1.51 milliseconds. While these changes may seem minuscule, they have the potential to disrupt various technologies and systems that rely on precise time measurements.
According to the Daily Mail, since 2020, Earth has been spinning slightly faster than expected, yet the cause behind this change remains a mystery. This recent acceleration contrasts sharply with the long-standing trend of the Earth’s gradual deceleration, primarily driven by the moon’s gravitational pull. Over millions of years, this effect has lengthened Earth’s days, which is essential for maintaining the current 24-hour cycle. For now, scientists are puzzled by the unexpected speed-up of Earth’s rotation. Leonid Zotov, a scientist at Moscow State University, stated, “Nobody expected this; the cause of this acceleration is not explained.” Despite ongoing efforts to identify a clear cause, researchers continue to explore various natural factors that might be influencing Earth’s spin, including the planet’s molten core, ocean currents, and atmospheric conditions.
Earth’s core, consisting of swirling molten metal, plays a crucial role in its rotation. The shifting of this liquid mass can affect the planet’s overall balance and shape. Just like a figure skater spins faster by pulling in their arms, changes in the distribution of mass within the Earth could alter its spin speed. Additionally, forces such as ocean currents and high-altitude winds—known as jet streams—move large amounts of mass around the planet, causing small but significant changes in Earth’s rotation.
Since 2020, Earth has been setting new records for the shortest days. On July 19, 2020, Earth recorded a day that was 1.47 milliseconds shorter than usual, and in subsequent years, similar records have been set. The fastest day on record so far occurred on July 5, 2024, when Earth’s rotation was 1.66 milliseconds faster than the standard 24-hour cycle. Researchers are carefully tracking these shifts using atomic clocks, which measure the “Length of Day” (LOD) with remarkable precision.
While these milliseconds might seem negligible, they are far from insignificant. Our global systems, such as GPS, communication networks, and financial markets, rely on precise time synchronization. Even the slightest variation in the Earth’s rotation can lead to glitches in these systems, affecting everything from satellite navigation to the functioning of mobile apps. Currently, the world uses Coordinated Universal Time (UTC) to standardize timekeeping. When Earth’s rotation slows down or speeds up, occasional adjustments, such as adding or subtracting a leap second, become necessary. However, a negative leap second would be an unprecedented change. If Earth’s rotation continues to speed up, scientists may be required to remove a second from the system, marking the first time in history that such an adjustment has been made.
