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Open Image ModalHow savvy are you about eclipses? You probably know that a solar eclipse occurs when the moon passes between the Earth and the sun. But did you know that the shadow of a solar eclipse travel at 1,100 miles an hour at the equator and up to 5,000 miles an hour at the poles? And that's just one of this slideshow's fascinating facts, as compiled by NASA scientist Sten Odenwald.Picture taken on Easter Island, 3700 km off the Chilean coast in the Pacific Ocean, on July 11, 2010. (credit:MARTIN BERNETTI/AFP/Getty Images)
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Open Image ModalDuring an eclipse, local animals and birds often prepare for sleep or behave confusedly. Picture taken in Bucharest, Romania on January 4, 2011. (credit:DANIEL MIHAILESCU/AFP/Getty Images)
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Open Image ModalBefore the advent of modern atomic clocks, studies of ancient records of solar eclipses allowed astronomers to detect a 0.001 second per century slowing down in Earth's rotation.Picture taken on July 22, 2009 from the observatory of the University of the Philippines in Manila. (credit:TED ALJIBE/AFP/Getty Images)
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Open Image ModalThe width of the path in which a total eclipse is visible is at most 167 miles wide.Picture taken at the Life-giving Trinity Russian Orthodox Cathedral in Moscow, Russia on January 4, 2011. (credit:OXANA ONIPKO/AFP/Getty Images)
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Open Image ModalThe longest duration for a total solar eclipse is 7.5 minutes.Picture taken on January 04, 2011 in Locon, northern France. (credit:PHILIPPE HUGUEN/AFP/Getty Images)
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Open Image ModalPartial solar eclipses can be seen up to 3,000 miles from the "track" of totality.Picture taken in Baihata village, 30 kms from Guwahati, the capital city of the northeastern state of Assam in India on July 22, 2009. (credit:BIJU BORO/AFP/Getty Images)
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Open Image ModalThe maximum number of solar eclipses (partial, annular, or total) is 5 per year, and there are at least 2 solar eclipses per year somewhere on the Earth.Picture taken in the Indian city of Varanasi on July 22, 2009. (credit:PEDRO UGARTE/AFP/Getty Images)
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Open Image ModalOnly partial solar eclipses can be observed from the North and South Poles.Picture taken over the statue of late Chinese leader Mao Zedong in Wuhan, Hubei province, China, on July 22, 2009. (credit:AFP/AFP/Getty Images)
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Open Image ModalLight filtering through leaves on trees casts crescent shadows as totality approaches. Picture taken on July 22, 2009 in Seoul, South Korea. (credit:Chung Sung-Jun/Getty Images)
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Open Image Modal"Shadow bands" are often seen on the ground as the eclipse's peak approaches.Picture taken on January 04, 2011 in Rennes, western France. (credit:DAMIEN MEYER/AFP/Getty Images)
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Open Image ModalDuring totality, the horizon is illuminated in a narrow band of light, because an observer is seeing distant localities not under the direct umbra, or area of darkness, of the Moon's shadow.Picture taken on January 4, 2011 in Old Damascus, Syria. (credit:LOUAI BESHARA/AFP/Getty Images)
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Open Image ModalLocal temperatures often drop 20 degrees or more near totality. Picture taken January 4, 2011 in Italy. (credit:Flickr: David Paleino)
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Open Image ModalEvery eclipse begins at sunrise at some point in its track and ends at sunset about half way around the world from the start point. Picture taken January 4, 2011 by the Hinode satellite. (credit:NASA Goddard Photo and Video, Hinode/XRT)
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Open Image ModalNearly identical eclipses (total, annual, or partial) occur after 18 years and 11 days, or every 6,585.32 days (Saros Cycle). Picture taken in Lahore, Pakistan on January 4, 2011. (credit:Arif Ali/AFP/Getty Images)