It was over so quickly! Earth records shortest day ever as 1.59 milliseconds shaved off 24-hour spin
Planet Earth has recorded the shortest day since measurements began.
The 1.59 millisecond shaved off the usual 24-hour spin on June 29 raises the prospect that a leap second must occur to keep the clocks aligned. This would be the first time global clocks have accelerated.
The Earth’s rotation is known to slow down, by 27 leap seconds needed to keep atomic time accurate since the 1970s. The last was on New Year’s Eve 2016, when the clocks paused to give Earth a chance to catch up.
There are other factors that can affect the length of Earth’s days, including snow that accumulates on the mountains in the Northern Hemisphere in winter and then melts in summer.
But since 2020, that phenomenon has reversed — the previous fastest day was -1.47 milliseconds on July 19 of that year. Humans can’t detect the change, but it could affect satellites and navigation systems.
Experts say the “Chandler Wobble” — a change in the Earth’s rotation on its axis — may be to blame. dr. Leonid Zotov of the Sternberg Astronomical Institute, Moscow, said: “The normal swing amplitude is about four meters at the Earth’s surface, but from 2017 to 2020 it has disappeared.”
Experts say the ‘Chandler Wobble’ – a change in Earth’s rotation on its axis – could be to blame
There are other factors that can affect the length of days on Earth, such as snow that accumulates on the mountains in the Northern Hemisphere in winter and then melts in summer.
Global warming is also thought to have an effect by melting ice and snow at a faster rate.
The International Earth Rotation Service in Paris monitors the planet’s rotation and will tell countries when to add or omit leap seconds, with six months’ notice.