Earth orbit slows no more, baffling scientists: In a phenomenon that has scientists puzzled, the Earth is right on schedule for a fifth straight year.
Experts agree that the rate at which the Earth travels through space has slowed ever so slightly for millennia. To make the world's official time agree with where the Earth actually is in space, scientists in 1972 started adding an extra "leap second" on the last day of the year.
For 28 years, scientists repeated the procedure. But in 1999, they discovered the Earth was no longer lagging behind.
