The Moon Is Drifting Away From Earth—And Scientists Say It's Making Our Days Last Longer
We've all wished for more hours in the day. Now, according to a new study published in the Proceedings of the National Academy of Sciences, that wish is coming true thanks to our moon, but it is going to take a little longer than we all want it to.
Reconstructing the history of Earth's relationship with the moon using astrochronology (astronomical theory + geological observation), researchers found that 1.4 billion years ago, days on Earth were around 18 hours long.
Back then, the moon was closer to our planet, which affected how Earth spun on its axis.
"As the moon moves away, the Earth is like a spinning figure skater who slows down as they stretch their arms out," said study co-author and professor of geoscience at the University of Wisconsin–Madison, Stephen Meyers.
At the current rate of around 3.82 centimeters each year, every century adds 2 milliseconds to an Earth day. That means that in another 200 million years Earthlings will have an extra hour to sleep, or fly, or whatever it is they do in the future.
But the point of the study wasn't to make us envious of this planet's future inhabitants. "One of our ambitions was to use astrochronology to tell time in the most distant past, to develop very ancient geological time scales," Meyers added.
"We want to be able to study rocks that are billions of years old in a way that is comparable to how we study modern geologic processes."
Millions of years of past climates are recorded in the sediments of ancient rocks, so developing a way to study rocks that are much older could present a more in-depth picture of what Earth was like.
"The geologic record is an astronomical observatory for the early solar system," Meyers said.
"We are looking at its pulsing rhythm, preserved in the rock and the history of life."