For millennia, people living in northern latitudes have looked skyward in wonder as shimmering curtains of green, red and violet light danced across the night sky. Known as the Aurora Borealis, or Northern Lights, this extraordinary phenomenon is one of nature’s most spectacular displays.
The name "aurora borealis" was coined in 1619 by the Italian astronomer Galileo Galilei, combining Aurora, the Roman goddess of dawn, with Boreas, the Greek god of the north wind. Long before science offered an explanation, however, Indigenous peoples had developed their own interpretations. The Inuit, Sámi and numerous First Nations cultures regarded the lights as spirits, ancestors, celestial fires or messages from the spirit world.
Between the 14th and 19th century, a period known as the “little ice age”, weather and climate were generally cooler in the north Atlantic than today. In an era when the night sky was largely free of artificial light, the aurora was an extraordinary sight. For many, it appeared as a divine sign. Welsh poet Robert Owen captured the sense of awe in 1749. He described the northern lights as a rhyfeddod hynod (“strange wonder”) and arwyddion cryfion Crist (“Christ’s strong signs”).
Science eventually revealed a less mystical, but equally astonishing, explanation. The Sun constantly emits a stream of charged particles known as the solar wind. When these particles reach Earth, most are deflected by our planet's magnetic field. Near the magnetic poles, however, some particles funnel into the upper atmosphere, colliding with oxygen and nitrogen atoms. These collisions release energy as light.
Different gases produce different colours. Oxygen high in the atmosphere creates the aurora's rare red glow, while lower-altitude oxygen generates the familiar green. Nitrogen can produce blue, purple and pink hues. The lights typically occur between 100 and 300 kilometres above Earth.
Auroral activity follows the Sun's approximately eleven-year solar cycle. During periods of intense solar activity, known as solar maximum, displays become brighter and visible much farther from the poles. Exceptional events have occasionally illuminated skies as far south as the Caribbean and Australia.
The most famous such event was the Carrington Event of 1859, the largest geomagnetic storm ever recorded. Telegraph systems around the world malfunctioned, operators received electric shocks, and auroras were reportedly bright enough to read newspapers by at midnight.
Today, the aurora has become a major tourism draw. Thousands travel annually to northern Norway, Iceland, Canada, Alaska and Finland hoping for a glimpse. Entire industries now cater to "aurora hunters", despite the inherent unpredictability of the lights.
Scientists continue to study auroras because they provide valuable insights into "space weather" – solar activity that can disrupt satellites, radio communications, power grids and GPS systems. In an increasingly technological world, understanding the aurora is no mere curiosity.
______________________
References
https://en.wikipedia.org/wiki/Aurora
https://theconversation.com/northern-lights-how-the-aurora-borealis-captivated-18th-century-minds-243076
https://www.nhm.ac.uk/discover/what-are-the-northern-lights-aurora-borealis-causes-explained.html
Images
1. “Essence of the Arctic Night" by Giulio Cobianchi. A full 360° panorama, made of two rows of shots taken at Haukland Beach, in Norway's Lofoten Islands, 2025
2. Galileo Galilei (1564–1642)
3. Frederic Edwin Church's 1865 painting Aurora Borealis
4. Photo credit: BBC Weather Watchers
5. Northern lights from the International Space Station. Credit: NASA
6. Diagram credit: spaceplace.nasa.gov
7. Typical auroral spectrum. Credit: spaceweather.gov
8. Auroral oval diagram. Credit: spaceweather.gov
9. Aurora borealis on Jupiter. Credit: NASA, ESA and J Nichols of the University of Leicester
10. Northern Lights over fort at Sitka, Alaska. Credit: Library of Congress
