A picture of a road with the northern lights above it.
Reuters/Alexander Kuznetsov
Wondrous space weather.
VAPOR TRACERS

NASA will release a colorful gas into the air to see how solar winds cause the northern lights

By Katherine Ellen Foley

The best part about astronomy is that it can unravel the mysteries of what makes our universe so beautiful.

This month, NASA scientists are teaming with Norwegian colleagues to fire up rockets from the northernmost launch sites in the world, Andøya and Svalbard. Their mission is to study the solar winds made up of super-hot gas and high-energy electrons that tickle the ionosphere, the layer of the Earth’s atmosphere that ranges from about 50 to 620 miles (75 to 1,000 km) above the planet.

Why the launch site matters

The location of these rockets in the sky—near the northern magnetic pole—is strategic: It’s one of the two places where Earth’s magnetic shield is weakest. All the high-energy electrons blown in by solar wind gather there when they’re shoved away from the rest of the planet by its strong magnetic field. These displaced electrons pack an energetic punch, and as they collide with gases like oxygen and nitrogen, they give off energy. We see the byproduct of these collisions as the gorgeous display of greens, blues, reds, and purples in the night sky as the Aurora Borealis in the northern hemisphere, and the Aurora Australis in the southern hemisphere.

The Auroral Zone Upwelling Rocket Experiment, or AZURE for short, hopes to better define the exact patterns of these solar winds, which happen whenever the sun gives off the flares that are a normal part of the sun’s 11-year rotation. To do so, the rockets will releasing gases that are colored and harmless—called vapor tracers—into the atmosphere. These tracer gases will then act like solar wind-pattern paintbrushes that astronomers can map.

The missions’ main goal

Tracking these patterns will allow astronomers to better plan for upwelling—moments when colder air in the ionosphere gets blown higher. On and near the surface of the Earth, the temperature of the air drops as we go up. But at the top layers of the atmosphere, colder air is heavier than warmer air.

We’d normally expect that nothing would disturb these temperature layers of gases, and yet scientists have noticed them swirl up. When cold air is suddenly pushed up (or warmer air is pushed down), they can disturb the orbits of satellites, spacecraft navigation, and even communication systems, Earther reports. “The only candidate we can think of for supplying the energy is the aurora,” Mark Conde, a space physicist at the University of Alaska, Fairbanks on the AZURE mission, told the publication.

Researchers are still waiting for exactly the right moment to launch the rockets. They need a plasma energy arm to reach out from the sun and generate the Aurora Borealis to see these wind patterns at all. So far, the skies have been quiet. They hope that  sometime before the launch window closes on March 17, the heavens will erupt in color when a bright flare reaches us—a celestial signal that the experiment can begin.