Auroras Shed Light On Space Secrets

A sounding rocket carrying Aerospace instruments launches into the northern lights. (Photo courtesy NASA/Goddard/Chris Perry.)

The auroras are more than just spectacularly pretty. They are a window into space’s mysteries, a window that a joint team from NASA’s Goddard Space Flight Center and The Aerospace Corporation recently took advantage of, using a suborbital rocket mission named VISIONS.

Aerospace and NASA employees traveled to Poker Flat, Alaska, in early February to wait for the northern lights to begin their enigmatic dance across the night sky. They had a two-week window in which to wait for the perfect conditions before launching the sounding rocket into the red and green depths of the aurora borealis. While the lights appear fairly often, the team wanted a strong magnetic storm to maximize the data collection. They finally got their chance Feb. 5.

A bountiful partnership

The VISIONS project (VISualizing Ion Outflow via Neutral atom imaging during a Substorm) began as a proposal between the two organizations more than three years ago.

When the Goddard team set out to measure the solar winds present within the aurora, they reached out to The Aerospace Corporation for the company’s capability to measure charged particles, said Dr. James Clemmons, principal director, Space Science Applications Laboratory.

“Study is an important concern for any spacefaring nation. NASA is interested in learning about these, and so is Aerospace,” said Clemmons, who was one of the handful of scientists from the Aerospace team to travel to Alaska. “We were looking at the drivers — the cause and effect — and NASA Goddard was looking at the effect only.”

Among the rocket’s instruments were two contributed by Aerospace — electromagnetic analyzers and the Rocket Auroral Imager, which was developed specifically for the VISIONS mission. The analyzers measured the energetic charged particle fluxes, and the imager photographed the aurora from space in four different wavelengths.

Looking to the sky

The auroras are natural light displays created when energetic charged particles collide. They exist primarily in high latitudes, the most famous of which are the aurora borealis and aurora australis — the northern and southern lights, respectively.

These light shows exhibit some of the unique features found deeper in space. There, in the auroral wind, oxygen atoms get heated enough to escape Earth’s atmosphere into outer space, at a fraction of the velocities normally needed overcome gravity.

“We wanted to know how and where are ions accelerated to escape velocities in the aurora zone below 1,000 kilometers, following a substorm onset,” Clemmons said. “VISIONS explored low-altitude ionospheric sources of magnetospheric ions.”

The Aerospace crew also hopes that understanding certain charged particles, which are not organically present on Earth, but are present elsewhere in space, will help them understand the effect these charged particles have on space equipment, and how engineers can guard the instruments against the sparks these particles can cause.

The auroras offer scientists a chance to learn about these phenomena from what is essentially Earth’s backyard, without the time, cost and risk of a more involved, extensive mission traveling to other areas where these things are also present.

“It is a fantastic display, and a fantastic laboratory for space physics, in an accessible place,” Clemmons said.

The rocket reached almost 470 miles above the Earth, and flew for 15 minutes before coming back down to the planet’s surface and landing in the Atlantic Ocean.

“It was only 15 minutes, but it was a good 15 minutes,” Clemmons said.

The next step

Although the team has just started scratching the surface of the data collected by VISIONS, they have high hopes for what they will discover.

Data collected and transmitted in that small 15-minute window gave the team enough information to keep them busy analyzing for the next year.

“We consider this successful. All our measurements worked well, and it looks like they are going to tell us something,” Clemmons said.

—Heather Golden