May 13, 2020
By John Murphy

For the next 81 days, (click here) the sun will go without setting in the northern Alaska city of Utqiagvik, formerly known as Barrow.

At 2 a.m. on May 11, the descended below the horizon in Utqiagvik just enough for the city to enter what's known as the civil twilight stage. Civil twilight occurs when the sun is about 6 degrees below the horizon and it's the first phase after sunset. During civil twilight, artificial lighting isn't necessary because sunlight is still illuminating the area, but the sun itself is no longer visible in the sky, according to the National Weather Service.

Sunset in Utqiagvik was short-lived, though.
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Just 45 minutes later, at 2:45 a.m, the sun rose above the horizon again - and it won't descend below the horizon until the early-morning hours on Aug. 1.

There are four phases of daylight after a sunset, the first being civil twilight and after that comes nocturnal twilight, which occurs when the sun is 12 degrees below the horizon. During nocturnal twilight, outdoor light from the sun will diminish to the point where activities will need artificial lighting to continue....