American cities entered the Sun for 66 days not seen
In Utqiagvik, the northernmost city of the United States in Alaska, the last sunrise in 2020 on November 18.
Prolonged darkness envelops the city in "polar night", a phenomenon that occurs in the north and south poles every winter. Because the Earth's axis is tilted, regions in the Arctic Circle can shift away from the Sun for days, weeks or months in a row between autumn equinox and spring equinox. In summer, by contrast, bright sunlight shines 24 hours a day in the "land of the sun in the middle of the night".
In the Northern Hemisphere, the date becomes shorter since the end of June. This effect is most pronounced in the north. The daytime shortest time is at the end of September, and as short as December, around the winter solstice.
On November 1, the day in Utqiagvik lasts 5 hours 42 minutes, the sun rises at 10:18 am and sets at about 4 pm. On November 18, the sun only appeared for 34 minutes, shining at noon and set at 1:29 ''. The sun does not rise above the horizon on the afternoon of November 18, but the dim glow of the sun disc remains in view. From now until the end of the month, Utqiagvik will only have a dark shadow as the Sun rises a few degrees below the horizon.
After that, however, the Sun will "disappear" until the end of January 2021. On the winter solstice on December 21, the Sun remained at 4.7 degrees below the horizon at noon and only reappeared on January 23.
Two months of darkness seemed long, especially in areas with harsh climates, with December average temperatures never exceeding 0 degrees Celsius. Before that, Utqiagvik was continuously lit up from May 11. to August 18. In the North and South Pole, the Sun only rises and sets once a year. The sun rises in spring equinox and sets in autumn equinox. In the Arctic, the continuous illumination lasts from March to September. During autumn and winter, darkness lasts for 6 months, only the light from the stars, moon and aurora. . Utqiagvik has the same number of solar hours as Miami, Sydney and Moscow.