NASA is set to launch a pair of rockets through an active aurora to study the natural light display.
Often spotted in a polar climate, aurora borealis (also known as the northern lights) are actually a source of heat—one which the Ion-Neutral Coupling during Active Aurora (INCAA) mission hopes to explore.
Here in Earth’s lowest atmospheric layer, the troposhere, air is made of neutral particles. Hundreds of miles above us, though, air begins to change character; energized by the sun’s unfiltered rays, once-neutral gas transforms into an electrically reactive state of matter known as plasma.
It’s unclear where natural gas ends and plasma begins; rather, the two populations intermix in what NASA called “an extended boundary layer,” where particles experience constant friction. “But active auroras turn everything up a notch,” the space agency said.
Auroras form when electrons from near-Earth space travel into our atmosphere, colliding with neutral particles and setting them alight. “It’s like storming the football field after a college game,” according to Stephen Kaeppler, assistant professor of physics and astronomy at Clemson University and principal investigator for the INCAA mission.
“People at the top of the stadium run toward the field, and as you get closer to the field, the crowd gets thicker and thicker,” he explained. “This is how it is for electrons facing the increasing neutral density of the upper atmosphere.”
Learning how much aurora influence that boundary layer is “key,” NASA said, to understanding how much energy they ultimately release into our upper atmosphere. Enter INCAA, which aims to measure how these natural phenomena change the layer where plasma meets neutral gas.
INCAA features two payloads, each mounted on a separate sounding rocket—small launch vehicles designed to spend a few minutes surveying space before falling back to Earth.
The team, situated at the Poker Flat Research Range in Alaska, expects to launch its rockets today in quick succession, reaching between 125 and 186 miles altitude to measure the temperature and density of plasma in and around the aurora.
