Norse Mythology Behind the Northern Lights

Look up at an Alaska aurora and someone will tell you the Vikings thought it was light glinting off Valkyrie armor. It is a wonderful story, but it almost certainly is not Viking. The Eddas barely mention the northern lights at all, and the one medieval Norse writer who did describe them reached for physics, not gods. Here is what the Norse sources actually say, where the popular northern lights mythology came from, and how you can see the real thing from Alaska.

Valkyries Riding Across the Sky

The best-known “Norse” aurora legend says the lights are the gleam of the Valkyries’ armor as they ride. Valkyries are genuinely Norse: in the Poetic and Prose Eddas they are Odin’s “choosers of the slain,” who bring the bravest fallen warriors to Valhalla, where those warriors wait to fight beside the gods at Ragnarök. But no Old Norse text links the Valkyries to the aurora. The connection appears in writing only in the modern era; it was popularized in the 1800s. It probably grew out of a passage in the Eddic poem Helgakviða Hundingsbana I, where light flashes in the sky and rays shine from the Valkyries’ spears as they appear to the hero Helgi.

That passage is worth a closer look. In Henry Adams Bellows’s 1923 translation, as Helgi rests after a battle, “Then glittered light from Logafjoll, / And from the light the flashes leaped,” and the Valkyries appear “High under helms on heaven’s field,” their mail red with blood, “And from their spears the sparks flew forth.” A nineteenth-century reader who already knew the aurora could easily see it in those lines. A Viking Age listener, however, had no reason to: the poem is describing armed women arriving from the sky, not a glow on the horizon. So the “Valkyrie lights” are a modern reading of an old poem, not a belief the Vikings held.

Heimdall Guarding the Bridge Bifrost

Another popular claim is that the aurora is Bifrost, the bridge between worlds. In Snorri’s Prose Edda, Bifrost is a strong, three-colored bridge, its red part burning fire, that joins Midgard, the world of humans, to Asgard, home of the gods. Snorri says plainly that it is what people call the rainbow. It is guarded by Heimdall, who needs less sleep than a bird, sees a hundred leagues by night as well as by day, and can hear grass growing. At Ragnarök he will sound the horn Gjallarhorn to warn the gods.

So Bifrost is a rainbow, not an aurora. The two are easy to confuse in a retelling, since both arch across the sky in bands of color. In the sources, though, Bifrost is a daytime bridge of three colors, and its fire is what keeps the giants from crossing. Nothing in Snorri suggests the shimmering green curtains of a winter night.

What the Norse Actually Said About the Northern Lights

So what did the Norse actually say? Surprisingly little. The sagas and Eddas are nearly silent on the aurora, perhaps because in Norway and Iceland it was simply part of the winter sky. The earliest detailed Norse description comes from the King’s Mirror (Konungs skuggsjá), written in Norway around 1250, which describes the “northern lights” (norðrljós) seen in Greenland and offers natural explanations: perhaps fire encircles the outer ocean, perhaps the sun shines up from below the horizon, or perhaps the Greenland ice has stored up so much power that it glows. Not a god in sight.

The King’s Mirror is a remarkable book for its time. It is written as a conversation between a father and his son, and the father treats the lights as a puzzle to be reasoned about, comparing them to the glow of a fire seen from far off and to the way the sun lights the sky before it rises. He even notes that the lights appear only at night, most often in the deepest darkness and seldom by moonlight, which is exactly what an Alaskan aurora watcher learns in the first winter (Larson’s 1917 translation, listed in the sources below). In other words, the one Norse text that studies the aurora reads more like early science than myth.

Northern Lights Mythology from Other Peoples

If the Vikings left the aurora alone, their neighbors did not. The Sámi of northern Scandinavia treated the lights with respect, and in later folklore it was unwise to whistle or wave at them. The Finnish name revontulet means ‘fox fires,’ from a tale of a fox whose tail sweeps sparks and snow into the sky. Many northern stories, in Europe and in North America alike, connect the lights with the spirits of the dead. These are real traditions, but they belong to other peoples. Most were recorded centuries after the Viking Age. Much of the northern lights mythology people repeat today comes from these neighbors, and mixing it into “Norse mythology” is how the Valkyrie story spread.

What Causes the Aurora Borealis?

Today we know what causes the aurora. Charged particles from the sun, steered by Earth’s magnetic field, slam into oxygen and nitrogen high in the atmosphere and make them glow green, red, and violet. Green comes from oxygen about 60 to 150 miles up; the rarer red from oxygen higher still; the violet and blue fringes from nitrogen. The brighter displays follow solar storms, which is why the aurora runs in cycles with the sun’s own eleven-year rhythm.

Seeing the Northern Lights in Alaska

Want to catch it yourself? Alaska is one of the best places on Earth to do it. Fairbanks lies under the auroral oval, the ring around the magnetic pole where the lights are most frequent. On a clear, dark night between late August and April, the odds there are good. Anchorage and the Mat-Su see the lights on stronger nights, especially away from city glow. Dress for the cold, get away from streetlights, face north, and give your eyes twenty minutes to adjust. The University of Alaska Fairbanks Geophysical Institute publishes a free aurora forecast, so you can plan the night before.

Even knowing the physics, the aurora still stops you in your tracks, and it is easy to see why people everywhere have told stories about it. Next time the sky starts to ripple, you can tell your friends the real northern lights mythology. The Valkyries are genuine Norse myth, the aurora connection is a modern tale, and a 13th-century Norwegian scholar was already hunting for a natural explanation. Have a favorite aurora night? Tell us about it in the comments.

Keep reading: where the Valkyries took the slain, in the Viking afterlife, and what waited for everyone else, in Hel and the afterlife.

Northern Lights Mythology: Questions and Answers

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