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 down until January 22, 2026.
Earth’s axial tilt causes this astronomical phenomenon. In astronomy, this axial tilt is referred to as obliquity is the angle between an object’s axis of rotation and its orbital axis, which is the line perpendicular to its orbital plane; correspondingly, it is the angle between its equatorial plane and orbital plane.
Earth’s axial tilt is about 23.5 degrees relative to its orbital plane and is primarily responsible for seasons and varies on a cycle of about 40,000 years.
In the absence of this tilt, the seasons would be much less extreme, or else they would not exist at all.
The Northern Hemisphere leans away from the sun in winter, and for communities located far enough north like Utqiagvik, the sun remains below the horizon for an extended period.
Around 5,000 people live in the neighbourhood.
Only natural light for the next two months will come from a faint twilight glow near the southern horizon and the spectacular lighting of the Aurora Borealis dancing in the sky above.
The polar night will also be followed by extreme cold, with temperatures often plunging well below zero degrees Fahrenheit.
This period of darkness is a prominent feature of life in the Arctic. But it is a temporary condition.
Around mid-May, the cycle of the seasons will be reversed and Utqiagvik will experience the extreme opposite weather of over 80 days of continuous daylight, known as the midnight sun.
For now, society is settling in for the long, dark winter, a testament to life in one of the planet’s most extreme environments.
