The day will officially be a bit longer than usual on Tuesday, June 30, 2015, because an extra second, or “leap” second, will be added.
“Earth’s rotation is gradually slowing down a bit, so leap seconds are a way to account for that,” said Daniel MacMillan of NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
VLBI, or Very Long Baseline Interferometry, is a technique that uses multiple radio telescopes to very precisely measure the Earth's orientation. It was originally invented back in the 1960s to take better pictures of quasars, but scientists soon found out that if you threw the process in reverse, you could measure how the ground beneath the telescopes moves around, how long days really are, and how the Earth wobbles on its axis as it revolves around the sun! Learn more about VLBI here!
For more information about NASA's Space Geodesy Project, visit http://space-geodesy.nasa.gov !
This video is presented in both stereoscopic 3D and standard 2D versions.
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How will the leap second affect computers?
