SCIENCE

Thanks to social media and the power of citizen scientists chasing the Northern Lights, a new feature was discovered recently. Nobody knew what this strange ribbon of purple light was, so … it was called Steve. (European Space Agency)

Use our resource to meet Steve, fox fire, and other oddities of the aurora.

Teachers, scroll down for a quick list of key resources in our Teachers Toolkit.

Discussion Ideas

• Steve is part of the Northern Lights, or aurora borealis. What are aurorae? Take a look at our encyclopedic entry for some help.
  • An aurora describes brightly colored bands of light, visible around Earth’s geomagnetic poles, caused by the solar wind interacting with particles in Earth’s magnetic field. Specifically:
    • The sun continually ejects electrically charged particles called ions. These particles race through the solar system as the solar wind. The solar wind is mostly deflected by Earth’s magnetosphere. (Without this protective layer, by the way, the solar wind would violently rip apart our atmosphere and stop all life on Earth. Thank you, magnetosphere!)
    • Although most of the solar wind is blocked by the magnetosphere, some ions become briefly trapped in ring-shaped holding areas. These areas, in a region of the atmosphere called the ionosphere, are centered around the Earth’s geomagnetic poles.
    • In the ionosphere, the ions of the solar wind collide with atoms of oxygen and nitrogen. The energy released during these collisions causes a colorful glowing halo around the poles—an aurora. Here’s a pretty picture of an aurora oval above Antarctica and the geomagnetic south pole.
      • The aurora around the north geomagnetic pole is called the aurora borealis (Northern Lights).
      • The aurora around the south geomagnetic pole is called the aurora australis (Southern Lights).
    • The most active auroras happen when the solar wind is the strongest. The solar wind is at its strongest when the sun is active, experiencing solar flares and coronal mass ejections. What are solar flares and coronal mass ejections? Watch our video study guide to find out.

• Citizen scientists were instrumental in documenting the aurora phenomenon called Steve. What are citizen scientists? Take a look at our encyclopedic entry for some help.
  • Citizen science is the practice of public participation and collaboration in scientific research to increase scientific knowledge. Through citizen science, people share and contribute to data monitoring and collection programs. Usually, this participation is done as an unpaid volunteer.
  • Citizen scientists with programs such as Aurorasaurus and Alberta Aurora Chasers were among those who spotted (and named) Steve. According to the ESA, citizen science hubs such as “the Aurorasaurus website make it possible for a large number of people to communicate about the aurora borealis. It connects citizen scientists to scientists and trawls Twitter feeds for instances of the word ‘aurora’. In doing so, it does an excellent job of forecasting where the aurora oval will be.”
  • Citizen science makes discoveries like Steve possible. “In 1997 we had just one all-sky imager in North America to observe the aurora borealis from the ground,” says Prof. Eric Donovan, who first studied Steve. “Back then we would be lucky if we got one photograph a night of the aurora taken from the ground that coincides with an observation from a satellite. Now we have many more all-sky imagers and satellite missions like Swarm so we get more than 100 a night.”

• Although citizen scientists identified Steve, the Swarm mission was essential to studying it. What is Swarm?
  • Swarm is a European Space Agency (ESA) mission. Swarm is a constellation of three identical satellites dedicated to studying Earth’s magnetic field and magnetosphere.
    • One Swarm satellite flew right through Steve, collecting data from its very cool electrical field instrument.

• So, what is Steve?
  • Steve is a bright, purplish arc of light that is quite distinct from the rest of the night sky and gauzy auroras.
  • Dr. Donovan and other ESA brainiacs associate Steve with a fairly common phenomenon involving the interaction of a very slow-moving ribbon of gas and a big temperature spike (about 3000° Celsius or 5400° Fahrenheit) about 300 kilometers (186 miles) above Earth’s surface.
    • Donovan says he has an idea of how Steve “gets its unique color and shape—but won’t spill the beans until an upcoming paper is published.” Stay tuned!
    • Update!! Steve is now an acronym: Strong Thermal Emission Velocity Enhancement. Steve has “an unusual level of electron temperature enhancement and density depletion,” indicating it’s part of a subauroral ion drift (SAID)—a phenomenon scientists were well aware of but didn’t realize could produce visible auroras.

TEACHERS TOOLKIT

National Geographic: Meet Steve, a Totally New Kind of Aurora

ESA: When Swarm Met Steve

Smithsonian: Amateur Skywatchers Spot New Atmospheric Phenomenon

Nat Geo: What are auroras?

Nat Geo: What is citizen science?

(extra credit!) Science: New science in plain sight: Citizen scientists lead to the discovery of optical structure in the upper atmosphere