The Sun continuously radiates charged particles. Some of these particles can get caught in the magnetosphere and rain down into the atmosphere, usually near the poles. There, these particles can collide with gases, creating colorful glowing lights.

“Think of the atmosphere as a giant neon sign,” said Rafael Mesquita, an atmospheric scientist at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, who studies the connection between the atmosphere and magnetosphere. “When charged particles flow into the atmosphere along the magnetic field lines, they ‘power up’ the gases in the sky, causing them to glow — much like how electricity excites the gases inside the tubes of a neon sign.”

Mesquita explains that aurora colors depend on how deep the charged particles penetrate the atmosphere. Red and green auroras form easily at higher altitudes, where oxygen is abundant. At lower altitudes, however, where nitrogen dominates, more energy is needed. This is where blue and pink auroras come to life.

Auroras are linked to electromagnetic currents known as auroral electrojets. To learn more about these fascinating flows, NASA is joining forces with scientists like Mesquita and others at APL on the Electrojet Zeeman Imaging Explorer (EZIE) mission.

   

Aurora Color	Altitude	Atmospheric Composition
Red	≥120 miles (≥200 km)	Oxygen
Green	60-120 miles (100-200 km)	Oxygen
Blue	60-120 miles (100-200 km)	Nitrogen
Pink	≤60 miles (≤100 km)	Nitrogen

   

   

“Meteors occur all the time,” said Erin Dawkins, a scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, who studies how tiny particles called space dust interact with the atmosphere. “They heat up and burn as they enter the atmosphere, and if these particles are large enough, we see the bright streaks known as meteors.”

Meteors are more visible at night because the dark sky provides contrast, like stars appearing after dark settles in. Dawkins explains that, beyond their beauty, studying meteors helps scientists see atmospheric motion and chemical changes over time, like ink in water. Scientists are working to trace meteors back to their origins, which will reveal more about their journey and, ultimately, tell a more complete story of the universe.

   

   

   

Sprite clusters can span 10 miles across and reach up to 30 miles in height. When they emerge, they resemble fantastical shapes like carrots and jellyfish. “They’re like snowflakes; none are identical,” said Burcu Kosar, a scientist at NASA Goddard who leads NASA’s Spritacular citizen science project.

Unlike regular lightning, sprites are relatively cold and difficult to see with the naked eye. To best capture one, point a camera toward a distant thunderstorm at night and wait for the magic (read: science) to happen.

When lightning strikes the ground, Kosar explains, a current travels from the cloud to the ground, transferring large amounts of charge. This suddenly creates an electric field at the base of the ionosphere, which electrifies nitrogen to produce a brief, spectacular red glow. After sunset, the ionosphere’s lower boundary rises by about 12 miles or more, which allows sprites to spark high in the sky.

   

    

   

The sudden removal of the Sun’s light creates waves in the atmosphere, similar to ocean waves. These waves can merge into large wind perturbations, particularly near the solar terminator, and can stretch for thousands of kilometers.

“The scale of it is massive,” says Claire Gasque, a research associate at the University of California, Berkeley, who measured these enormous solar terminator waves for the first time. “It’s about 3,000 kilometers across — more than half the width of the continental United States.” These waves likely form due to temperature gradients caused by the solar terminator, though the exact mechanism remains unknown.

Solar terminator waves occur in the upper regions of the atmosphere where satellites operate. Gasque notes that understanding these waves is crucial as society becomes more dependent on space-based infrastructure like navigation and communications satellites.