Many jokes are made about creating just one more hour in the day, but that will eventually become a reality. After a review of celestial data spanning 27 centuries, a team of astronomers has determined that Earth’s orbit slows almost two milliseconds every 100 years. If the slowdown continues—and it’s expected to—Earth will eventually experience an extra hour each day. Some careful math helped researchers estimate how long it might take for the orbit to slow enough to create a whole new hour.

earth orbit, earth's orbit, slowing down earth orbit, earth day 25 hours, leslie morrison, durham university, united kingdom Nautical Almanac, uk Nautical Almanac

Collecting ancient documentation of celestial events, such as eclipses, was no small task. Researchers at Durham University and the UK’s Nautical Almanac Office collated data on events from 720BC to 2015, a span of 2,735 years. The oldest records came from Babylonian clay tablets written in cuneiform, with more added from ancient Greek texts, and scripts from China, medieval Europe, and the Arab region.

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Leslie Morrison is an astronomer and co-author of the study, which was just published in the journal Proceedings of the Royal Society. Morrison and his team evaluated nearly 3,000 celestial records in order to arrive at the estimated orbital slowing rate of 2ms per century. Although it’s been long known that the Earth’s orbit is gradually slowing, this is the first study to produce an estimated rate of that change. The study results also discuss some of the factors in the Earth’s orbital slowdown, including the tidal braking effect caused by the moon’s gravity, changes in the world’s sea levels, and the electromagnetic forces between Earth’s core and its rocky mantle.

Don’t start making plans for how to spend your extra hour. According to the study results, it will be another two million centuries before Earth’s day lengthens to 25 hours.

Via The Guardian

Images via NASA (1, 2)