On Wednesday, June 29, 2022, the day was shorter by 1.59 milliseconds compared to a full 24-hour day, marking a significant moment since scientists began using atomic clocks to measure the Earth’s rotation speed.
The Earth’s rotation speed can change due to various factors. Photo: Joecicak/iStock
The previous record was set on July 19, 2020, when the Earth completed a rotation that was 1.4602 milliseconds shorter than a full 24 hours. According to the International Earth Rotation and Reference Systems Service (IERS), on July 26, 2022, the Earth nearly broke the record again with a day that was shorter by 1.50 milliseconds.
The Earth completes one rotation in approximately 24 hours. However, the length of a day varies due to several factors. Tidal forces between the Earth and the Moon stretch the day and make it longer. Every 100 years, the Earth loses a few milliseconds to complete a rotation. The internal movements of the planet, the atmosphere, and satellites also affect the length of the day.
However, in recent years, it seems that the duration of a day is getting shorter.
Since 2020, the Earth has broken several speed records. The year 2020 recorded 28 days among the shortest ever documented since the 1960s. Experts are not entirely sure of the exact reasons, but some suggest it may be due to changes in the rotation axis.
Understanding the complex movements of our blue planet, especially if they relate to long-term cycles, can take a significant amount of time. Fortunately, most of the impacts of these fluctuations are negligible. If the accumulated discrepancies over several months or years become too large, the IERS may add a leap second to the official time. The most recent leap second was added on December 31, 2016.
