"What Happens When ‘The Sun Throws A Glitter Bomb’" Excerpt Transcript Excerpt from May 5, 2017 episode of Science Friday. ​ ​

FLORA LICHTMAN: This is Science Friday. I'm Flora Lichtman. Every so often, people living in the upper ​ latitudes get a celestial treat, the Aurora. It's also known as the Northern or Southern Lights, depending on your hemisphere.

But last year, something unexpected happened. Aurora chasers in Alberta, Canada saw a weird thing in the sky, a purplish streak, maybe a kind of Aurora. And they named it Steve. Of course they did.

My next guest helped to create an app that connects observations made by citizen scientists with researchers hungry for Aurora data. It's called Aurorasaurus. Joining me now is Dr. Liz MacDonald, space plasma physicist at NASA and founder of Aurorasaurus.org Welcome.

LIZ MACDONALD: Hi, thanks for having me. ​

LICHTMAN: What is Steve? ​

MACDONALD: So Steve is a great story. It's something that was observed across Alberta, Saskatchewan. ​ And it was given a different name initially. It's a very thin, purplish kind of arc that can go across the sky in an east-west direction.

LICHTMAN: It looks more like a Francesca to me. ​

MACDONALD: And it sometimes has a little bit of green to it as well. And it's quite a bit further south than ​ where most of the Aurora occurs. And people who are enthusiastic Aurora chasers, just like eclipse chasers, they actually captured it when they were out looking at Aurora. That was in Canada, much further north. And they said, what is this thing?

And so, through projects, we've been connected to some of these enthusiast groups that are organized on Facebook and Twitter. Alberta Aurora Chasers is the one that discovered this phenomenon. And we had conversations with them about how this is not likely to be what the common name was, which was a proton arc.

They connected with our team at Aurorasaurus and also scientists at the University of Calgary. And they just came up with a new name for it. It's actually based on an animated kids movie from Canada, where some characters don't know what something is. It's like different animals.

And so this group is really fun. And they said, let's call it Steve for a while and collect more observations. And that's really where this became really exciting to document, that Steve is actually not a one-time thing. It's a scientific phenomenon that can be documented in a rigorous way through citizen science and further investigated.

LICHTMAN: Is Steve an Aurora, though? What is Steve? ​

MACDONALD: So we are still working to figure out what is causing it. It is a long way further south than most ​ of the normal Aurora. And it's probably excited by light. Most aurora is excited by particles from way further out in space, following the Earth's magnetic field lines, and hitting the upper atmosphere, and causing some light.

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And so there are a couple that could be happening with Steve. Or it's possible that the upper atmosphere itself is chemically exciting some of the light here. And that's something that we're still piecing together from the satellite observations and some of these really interesting DSLR camera observations to further understand, as well as other ground-based camera observations, scientific observations.

LICHTMAN: Was it in the sky before and just we didn't see it because we weren't looking in the visible range ​ or something?

MACDONALD: We've been looking in the visible range, but not in this location, which the technical term is ​ sub-auroral. But really what this means is across the US border kind of latitudes. And the scientists missed it largely. Some people had seen it. But it hadn't been published that we know of yet.

Now people have better cameras. They have smartphones. They have Facebook and Twitter. And so all of these things together have combined to really help us connect in unique ways and improve our understanding of the system and make a discovery, really, with people's help, for a much better understanding of this rare kind of Aurora.

LICHTMAN: That's cool. Is there a simple way to describe how an Aurora is formed? ​

MACDONALD: The normal Aurora, as I said, is driven by the sun, starts up from the sun. One way I like to ​ describe it is thinking of a glitter bomb of charged particles coming from the sun. And--

LICHTMAN: Oh, I'm so glad that we asked. A glitter bomb. ​

MACDONALD: But the glitter is actually all invisible until the very end of this chain reaction that causes the ​ Aurora. And it travels an enormous distance. It travels 93 million miles out from the sun in all directions, and sometimes hits towards Earth, where it interacts with the Earth's magnetic field region. And, eventually, that energy is released in an oval shape at the high latitude regions, where it then creates the light of the Aurora and all of this beauty and dynamics that you can see.

LICHTMAN: I'm really glad that you gave us the glitter bomb analogy. I will never look at an aurora the same ​ way. Thank you, Liz MacDonald.

MACDONALD: Thank you very much. And thanks to all the citizen scientists who have been contributing to ​ Aurorasaurus and other projects like that.

LICHTMAN: Liz MacDonald is a space plasma physicist at NASA and founder of Aurorasaurus-- ​ Aurorasaurus.org. Resource And you can download the Aurorasaurus app, too.

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