& # 39; Steve & # 39 ;: the mysterious purple aurora that rivals the northern lights | Science

A group of citizen scientists in Alberta, Canada, was not sure what the bright purple (sometimes green) arch was in the night sky they had been photographing. Nor were scientists Elizabeth MacDonald, a space physicist at NASA, and Eric Donovan, an associate professor of physics and astronomy at the University of Calgary; The group ̵

1; known as Alberta Aurora Chasers, who photographs the Northern Lights, or Northern Lights – showed them their photos in a pub. Donovan told them it was not an aurora of protons (the northern lights are usually the result of the collision of electrons with gases in Earth's atmosphere), as they had thought. "They picked up this beautiful picture of this thing," Donovan told the New York Times last year. "And I think, I do not know what that is, but it's not the proton aurora." I needed a name: "Steve" sounded as good as any other. [It was inspired by a scene in the 2006 animation Over the Hedge, in which the animal characters are confronted with a mysterious row of shrubs.]

  & # 39; Steve & # 39; (strong increase in the thermal emission rate) looks like a thin purple ribbon of light

& # 39; Steve & # 39; (strong increase in the thermal emission rate) is seen as a thin ribbon of purple light. Photography: Megan Hoffman / Nasa

The phenomenon now has a countdown of an official name: strong increase in thermal emission speed (Steve, for short). It can be observed further south than the northern lights and is believed to be, according to a recently published article, "an optical manifestation" of another phenomenon, the sub-auroral ions drift. Steve is a visible strip of ionized gas, traveling at 6.4 km (4 miles) per second.

Last week, NASA called on citizen scientists and photographers to help with their research on Steve and report sightings to the Aurorasaurus project. It is, Donovan has said, "a truly new era" of collaboration between scientists and amateur professionals.

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