It was over so quickly! Earth records its shortest day ever as 1.59 milliseconds were shaved off of its 24-hour rotation
Planet Earth has recorded its shortest day since records began.
The 1.59 milliseconds subtracted from the usual 24-hour rotation 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 would be sped up.
The Earth’s rotation is known to be slowing, taking 27 leap seconds to keep atomic time accurate since the 1970s. The last was on New Year’s Eve 2016 when the clocks stopped for a second to allow the earth to catch up.
There are other factors that can affect the length of days on Earth, including snow that accumulates on northern hemisphere mountains in winter and then melts in summer
But since 2020, this phenomenon has reversed – the previously fastest day was -1.47 milliseconds on July 19 this year. Humans can’t see the change, but it could affect satellites and navigation systems.
Experts say the “Chandler Wobble” – a change in the way the Earth rotates on its own axis – could be to blame. dr Leonid Zotov from the Sternberg Astronomical Institute, Moscow, said: “The normal wobble amplitude is about four meters at the surface of the earth, but from 2017 to 2020 it has disappeared.”
Experts say the “Chandler Wobble” – a change in the way the Earth rotates on its own axis – could be to blame
There are other factors that can affect the length of days on Earth, including snow that accumulates on northern hemisphere mountains in winter and then melts in summer.
Global warming is also believed to have an impact by melting ice and snow faster.
The International Earth Rotation Service in Paris monitors the planet’s rotation and gives countries six months’ notice when leap seconds need to be added or removed.