The northernmost city in the United States has officially entered its annual period of perpetual twilight.
Utqiagvik, Alaska, began its “polar night” this week, marking the start of approximately 65 days without direct sunlight.
In the region, the sun set on November 18 and will remain so until January 22, 2026.
The axial tilt of the Earth causes this astronomical phenomenon. In astronomy, this axial inclination is known as obliquity and is the angle between an object’s axis of rotation and its orbital axis, which is the line perpendicular to its orbital plan; Equivalently, it is the angle between its equatorial plane and its orbital plane.
The axial inclination of the Earth is about 23.5 degrees in relation to its orbital plane and is mainly responsible for the seasons and varies in a cycle of about 40,000 years.
Without this tilt, the seasons would be much less extreme or not exist at all.
The northern hemisphere moves away from the sun during winters, and in communities located far enough north like Utqiagvik, the sun remains below the horizon for an extended period.
About 5,000 people reside in the neighborhood.
For the next two months, only natural light will come from a faint afterglow near the southern horizon and the spectacular illumination of the northern lights dancing across the sky.
The polar night will also be followed by extreme cold, with temperatures often falling well below zero degrees Fahrenheit.
This period of darkness is a prominent feature of life in the Arctic. But it is a temporary state.
In mid-May, the cycle of the seasons will reverse and Utqiagvik will experience the opposite extreme weather with more than 80 days of continuous light, known as the midnight sun.
For now, the community is preparing for the long, dark winter, a testament to life in one of the most extreme environments on the planet.
