Longest lunar eclipse of the century coming Friday

On Friday skywatchers in several regions of the world will get to witness the longest total lunar eclipse of the 21st century.

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The July 27 eclipse will be fully visible for 1 hour and 43 minutes and partially visible for 3 hours and 55 minutes from parts of South Africa and most of Africa, the Middle East and Central Asia.

According to timeanddate.com, the eclipse will peak at 8:21 p.m. UTC (or 4:21 p.m. EST) and the full eclipse will end at 9:13 p.m. UTC (5:13 p.m. EST).

During a lunar eclipse, Earth’s shadow blocks the sun’s light, which otherwise reflects off the moon. A total lunar eclipse occurs when Earth’s dark umbral shadow completely covers the moon.

As the planet casts its shadow, the moon will emerge orange — or in some areas — blood-red.

Why? Well, the blue skies during the day are a result of Earth's nitrogen-rich atmosphere, which "takes white sunlight, a mixture of all colors of the spectrum, and scatters around the blue colors," according to Business Insider. "Around sunset and sunrise, the light reaching our eyes has been more thoroughly scattered, so much that blues are nearly absent. This makes the sun and its light appear more orange or even red."

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"Total eclipses are a freak of cosmic happenstance," Space.com reported. "Ever since the moon formed, about 4.5 billion years ago, it has been inching away from our planet (by about 1.6 inches, or 4 centimeters per year). The setup right now is perfect: the moon is at the perfect distance for Earth's shadow to cover the moon totally, but just barely. Billions of years from now, that won't be the case."

The July 27 eclipse will be the second lunar eclipse of the year. The first occurred on Jan. 31 and gave way for a super blue blood moon, when the full moon passed through the Earth's shadow for a total lunar eclipse and gave off a reddish tint.

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Unfortunately, the United States will miss out on the celestial spectacle this week and will have to wait until July 2020 to witness a lunar eclipse, according to NASA.gov.