Eclipse-chasing scientists to take off from Tucson for special mission

UPDATE (4/4): Astrophycisist Jenna Samra will be speaking at the Flandrau Science Center and Planetarium Saturday evening to discuss the ACES mission and upcoming total solar eclipse.

—

People across America will be watching next week’s total solar eclipse. But a special group of scientists will be watching from the skies, hoping to advance research in infrared astronomy.

The Colorado-based crew is now preparing for that complex flight in Tucson. On Eclipse Day, April 8, they will take off from Tucson International Airport and fly to the eclipse’s path of totality, over Texas.

The team will use the National Science Foundation and National Center For Atmospheric Research Gulfstream V aircraft, which will stay at Tucson’s Million Air Luxury Jet Center this week.

Jenna Samra is a principal investigator and instrument scientist, affiliated with the Center for Astrophysics, Harvard & Smithsonian.

She flew during solar eclipses in 2017 and 2019, describing those experiences as “wild.”

“It’s terrifying, but it’s also, there’s this feeling as the sun starts to eclipse, you just can’t believe you’re here,” she explained.

Now, she’s leading this mission. She designed the optics for the Airborne Coronal Emission Surveyor—or ‘ACES’—a new instrument that captures infrared light from the sun’s outermost atmosphere, called the corona.

During the eclipse, the light from the sun’s outer atmosphere travels through a special airplane window made of sapphire, so infrared light can pass through it.

It then bounces off a mirror into the instrument, which separates the light into spectra and records infrared data. The instrument can be adjusted and moved based on the position of the plane relative to the sun.

The sun is so bright, scientists only have a chance to get this detailed of a look at the corona’s infrared light during a total solar eclipse.

Scientists hope this mission will reveal more about the solar magnetic field, which is so powerful it can even cause blackouts or disrupt wireless communications on Earth.

“The sun, it’s bright. It’s warm. It’s the giver of life, basically,” said Chad Madsen, an astrophysicist with the Center for Astrophysics, Harvard & Smithsonian. “But at the same time, it’s a self-sustained, thermo-nuclear explosion in space that we have to live next to.”

This week, the team will do two test flights over Texas and visit schools in the area to discuss the eclipse and the upcoming mission.

Tucson was chosen as the launching point for the mission based on a few factors. It is close to the path of totality without being inside it, which the crew says is important as increased air traffic in the path of totality caused issues during previous eclipse flights.

It also has a prominent astronomy community and the proper facilities to house the aircraft.

“With the University of Arizona and a lot of the other astronomical institutions that are around, it’s the perfect area to do a lot of educational outreach, especially on this kind of very niche topic of infrared astronomy,” said Madsen.

On eclipse day, an eight person crew will fly at 47,000 feet to avoid weather and other air traffic. The flight path was determined by the ACES instrument, as well as the eclipse's length and angle.

The mission took years of planning, just to see the total eclipse for about six minutes.

“This took scientists, engineers, it took the pilots and the technicians and the mechanics,” said Samra. “A huge number of different roles to get this thing flying in the eclipse.”

“When it comes to the eclipse, you can’t reschedule the eclipse,” Madsen added. “So everything has to be rehearsed, has to be on time, has to be perfect. So you really learn a lot about how to do these very high-risk, high-precision missions.”