The shortest day ever recorded is approaching as Earth’s rotation speeds up faster than usual, scientists warn. This means our days will be slightly shorter than normal in the coming weeks.
Earth spins about 365 times per year, which is why we have that many days in a year. However, this number has changed throughout history due to things like sea level shifts, movements inside Earth, and the Moon moving away.
Currently, Earth is spinning faster, and no one knows exactly why. Graham Jones, an astrophysicist from the University of London, says this acceleration might happen on July 9, July 22, or August 5, making days shorter by up to 1.5 milliseconds.
Though these tiny changes seem small, they can affect GPS and timekeeping systems. Leonid Zotov from Moscow State University says this speed-up was unexpected and can’t be explained by ocean or atmospheric changes. The cause might be something inside Earth.
Earthquakes also influence Earth’s spin. The 2011 earthquake in Japan moved Earth’s axis and shortened days. NASA’s Dr. Richard Gross compared this to a figure skater pulling in her arms to spin faster, as the quake shifted Earth’s mass closer to its rotation axis.