They just got a little shorter thanks to the Chile earthquake this weekend:
The earthquake that killed more than 700 people in Chile on Feb. 27 probably shifted the Earth’s axis and shortened the day, a National Aeronautics and Space Administration scientist said.
Earthquakes can involve shifting hundreds of kilometers of rock by several meters, changing the distribution of mass on the planet. This affects the Earth’s rotation, said Richard Gross, a geophysicist at NASA’s Jet Propulsion Laboratory in Pasadena, California, who uses a computer model to calculate the effects.
“The length of the day should have gotten shorter by 1.26 microseconds (millionths of a second),” Gross, said today in an e-mailed reply to questions. “The axis about which the Earth’s mass is balanced should have moved by 2.7 milliarcseconds (about 8 centimeters or 3 inches).”
So feel free to clock out 1.26 microseconds early today.