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 about 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 tilt is called obliquity. This is the angle between an object’s axis of rotation and its orbital axis, which is the line perpendicular to its orbital plane; equivalently, it is the angle between its equatorial plane and its orbital plane.
The Earth’s axial tilt is approximately 23.5 degrees relative to its orbital plane and is primarily responsible for the seasons and varies on a cycle of approximately 40,000 years.
Without this tilt, the seasons would be much less extreme, or even not exist at all.
The Northern Hemisphere moves away from the sun during winters and for communities located quite north like Utqiagvik, the sun stays below the horizon for an extended period of time.
Around 5,000 people reside in the neighborhood.
For the next two months, only natural light will come from a faint twilight glow near the southern horizon and the spectacular illumination of the Northern Lights dancing in the sky above.
The polar night will also be followed by extreme cold, with temperatures often falling well below zero degrees Fahrenheit.
This period of darkness is an important feature of life in the Arctic. But it is a temporary state.
Around mid-May, the cycle of the seasons will be reversed and Utqiagvik will experience extremely opposite weather with over 80 days of continuous light, known as the midnight sun.
For now, the community settles in for a long, dark winter, a testament to life in one of the most extreme environments on the planet.
