The planet’s rotation fluctuates as it travels around the sun, and measurements suggest we’re losing more than a millisecond during the long days of summer.

Atomic clocks — among the most precise instruments humans have ever built — have been keeping track of Earth’s spin since the 1950s. But what they show today is unexpected. Our planet, which for decades had been slowing down in its rotation, is suddenly speeding up.

The world stands on the brink of a momentous event as Earth’s rotation is expected to accelerate, resulting in the shortest day in history. This unforeseen quickening of our planet’s spin has left scientists both perplexed and intrigued,