The city of Utkiajvik in the US state of Alaska witnessed its last sunset for the year 2020, as the sun was set for 66 days in a strange astronomical phenomenon that recurs every year at this time.
In detail, the National Weather Service in Alaska tweeted on Twitter, saying: "At 1:30 pm Alaska time, the sun will set for Utkiajvik, which will enter 66 days of polar darkness. The sun will return again on January 23, 2021."
Polar darkness occurs as a result of the Earth's tilting away from the sun during winter, when no disk of the sun is visible above the horizon at all. The opposite of this phenomenon occurs during the warm seasons in the northern hemisphere, from May until August when the sun does not set for more than two months.