Mysterious White Streaks in Northern Lights Spark New Research

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Scientists have spotted strange grayish-white lights woven into the northern lights, adding a new twist to aurora research. These ghostly streaks sometimes appear alongside the usual red and green auroras, but they are not auroras themselves. Instead, they might be related to a mysterious phenomenon called STEVE, which is a purplish light streak in the sky.

The discovery was made by scientists at the University of Calgary, who were reviewing images from the TREx mission. TREx is a Canadian program that uses cameras to study the space around Earth. One day, space physicist Emma Spanswick noticed something unusual—a grayish-white patch in the sky. After looking at more images, the team found similar white lights in auroras between 2019 and 2023, particularly over Rabbit Lake and Lucky Lake in Saskatchewan.

These white streaks appeared next to red and green auroras or in places where colorful auroras had just faded. The scientists found that the white lights were different from normal auroras. Instead of glowing with specific red or green light, the white lights glowed across all wavelengths, which is called continuum emission.

This glow looked very similar to the light produced by STEVE, a mysterious mauve light band that runs across the sky. STEVE is thought to form when fast-moving plasma heats up the atmosphere, causing it to glow. The newly discovered white streaks in the aurora might also be the result of heating, but scientists are still unsure why this happens in certain areas and not others.

The discovery raises more questions about what causes these unusual lights. Researchers believe that both the white streaks in the northern lights and STEVE could share a similar chemical process. However, the exact cause of the heating is still a mystery.

Space physicist Claire Gasque, who studies STEVE, says that learning more about the white streaks in the auroras could provide important clues to understanding how STEVE forms. While the white lights are patchy, unlike the neat arc of STEVE, studying them might help scientists figure out the chemistry behind both phenomena.