UPDATE 4/7/2022: The two INCAA rockets launched at 4:47 a.m. and 4:50 a.m. AKDT (8:47 a.m. and 8:50 a.m. EDT), reaching a peak altitude of 211 miles (340 km) and 129 miles (208 km), respectively. The data is currently under review by the science team.
If you see the northern lights overhead, chances are you are in a chilly, polar climate. But the cold-weather delights, also known as aurora borealis, high above you are actually an important source of heat. A new NASA mission hopes to fly through an active aurora to study this energy exchange process up close. The launch window for Ion-Neutral Coupling during Active Aurora, or INCAA mission, opens at the Poker Flat Research Range in Poker Flat, Alaska, on March 23.
As residents of the troposphere, Earth’s lowest atmospheric layer, we’re used to air made of neutral particles. The oxygen and nitrogen we breathe are magnetically balanced atoms and molecules with all their electrons accounted for. But hundreds of miles above us, our air begins to fundamentally change character. Energized by the Sun’s unfiltered rays, electrons are pried from their atoms, which then take on a positive charge. A once-neutral gas transforms into an electrically reactive state of matter known as plasma.
There is no hard cutoff where neutral gas ends and plasma begins. Instead, there is an extended boundary layer where the two populations intermix. Daily winds and magnetic perturbations send the two populations of particles in different directions, occasionally colliding – and creating some interesting physics as a result.
“Friction is a great analogy,” said Stephen Kaeppler, assistant professor of physics and astronomy at Clemson University in South Carolina, and principal investigator for the INCAA mission. “We all know that we rub our hands together, you’re going to get heat. It’s the same basic idea, except we’re dealing with gases now instead.”