Our days are about to get shorter than ever before, scientists warn, because Earth’s rotation is speeding up. This means the shortest day in recorded history could happen within weeks.
Earth completes roughly 365 spins on its axis each year, which gives us the number of days in a year. But this number has fluctuated over time due to many influences, including sea level changes, internal Earth movements, and the Moon drifting away.
Right now, Earth’s spin is accelerating unexpectedly. Graham Jones, an astrophysicist at the University of London, predicts that this speed-up could take place on July 9, July 22, or August 5, shortening the day by around 1.3 to 1.5 milliseconds.
Though this change is tiny, it could impact GPS systems and precise timekeeping. According to Leonid Zotov from Moscow State University, scientists don’t yet know why Earth is spinning faster, and current models of oceans and atmosphere don’t explain it. The cause may be deep inside the planet.
Natural disasters like earthquakes can also speed up Earth’s rotation. The 2011 Japan earthquake moved Earth’s axis and shortened days. NASA’s Dr. Richard Gross explained this by comparing it to a spinning skater pulling in their arms to turn faster—the quake shifted Earth’s mass closer to its rotation axis.
Scientists expect Earth’s rotation to slow down again eventually, but they aren’t sure when.
