Posted: Mar 2, 2010 10:31 AM by Associated Press
Earth's days may have gotten a little bit shorter since the earthquake in Chile. But don't feel bad if you haven't noticed.
A NASA scientist says the difference would be only about one-millionth of a second. Richard Gross and his colleagues at the Jet Propulsion Laboratory in Pasadena, Calif., calculated that Saturday's quake shortened the day by 1.26 microseconds. A microsecond is one-millionth of a second.
An earthquake can make Earth rotate faster by nudging some of its mass closer to the planet's axis. That's the same way that ice skaters speed up their spins by pulling in their arms.
The length of a day is the time it takes for the planet to complete one rotation - 86,400 seconds or 24 hours.