STEVE the aurora makes its debut in mauve

Citizen scientists captured images of the newly found light show


STEVE APPEARS  A purplish and green band of light known as STEVE, shown here with the Milky Way, is a new kind of aurora that appears in the sky during displays of the northern lights.

Krista Trinder

Meet STEVE, a newfound type of aurora that drapes the sky with a mauve ribbon and bedazzling green bling.

This feature of the northern lights, recently photographed and named by citizen scientists in Canada, now has a scientific explanation. The streak of color, which appears to the south of the main aurora, may be a visible version of a typically invisible process involving drifting charged particles, or ions, physicist Elizabeth MacDonald and colleagues report March 14 in Science Advances.

Measurements from ground-based cameras and a satellite that passed when STEVE was in full swing show that the luminous band was associated with a strong flow of ions in the upper atmosphere, MacDonald, of NASA’s Goddard Space Flight Center in Greenbelt, Md., and colleagues conclude. But the researchers can’t yet say how a glow arises from this flow.

Part of a project called Aurorasaurus (SN Online: 4/3/15), the citizen scientists initially gave the phenomenon its moniker before its association with ion drift was known. MacDonald and colleagues kept the name, but gave it a backronym: “Strong Thermal Emission Velocity Enhancement.”

We’ll just stick with STEVE.

SKY SHIMMERS  A mauve and green streak, lightning the sky at Helena Lake Ranch in Canada, was captured in this video by a citizen scientist. The phenomenon is a new type of aurora, dubbed STEVE, that’s associated with the flow of charged particles in the upper atmosphere.

Physics writer Emily Conover has a Ph.D. in physics from the University of Chicago. She is a two-time winner of the D.C. Science Writers’ Association Newsbrief award.

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