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From left, Don Hampton, Hans Nielsen and Peter Delamere gather in Nielsen’s office at the ������ Geophysical Institute in November 2024. Nielsen has had the same office since 1970.

By Rod Boyce

According to physics Professor Peter Delamere, solving big scientific puzzles always starts small. “Science is always little steps,” he said. “It’s a big foundation that you’re trying to build up.”

Those steps often mark a climb that began a good distance back in time — and require more than one climber.

For Delamere and colleague Don Hampton at ������ Geophysical Institute, those steps in their field of aurora research began with Professor Emeritus Hans Nielsen, their ������ graduate student adviser through the mid-1990s.

Today, Delamere and Hampton, a research associate professor, occupy office space on the ������ Elvey Building’s seventh floor — the Space Physics and Aeronomy Group floor.

And their former adviser is there, too, in the office he has occupied since June 1970, keeping busy in their shared field of researching the aurora and other phenomena occurring in the upper atmosphere, near-Earth space and beyond.

All three scientists have been studying various aspects of the aurora for years. Hampton and Delamere earned their doctorates in 1996 and 1998. They returned to ������ after work elsewhere following their doctorates — Hampton in 2006 and Delamere in 2012.

One major experiment building on years of work by their former adviser and now colleague will have its first major results published by year’s end.

It’s another of those little steps that Delamere mentioned.

But this step was actually quite big.

The Kinetic-scale Energy and momentum Transport experiment, or KiNET-X, launched May 16, 2021, from NASA’s Wallops Flight Facility in Virginia aboard a 5-ton BlackBrant XII unguided sounding rocket.

Within the 65-foot-tall rocket sat several instruments designed to help answer a decades-old physics question about the aurora of Earth and other planets in our solar system.

Delamere led the mission with Hampton serving as one of several co-investigators. Hampton’s specialty is using optical instruments to tease out information from the aurora’s light, particularly during low light.

The KiNET-X mission’s goal: Trying to understand how the relatively low energy of the solar wind becomes the high energy that creates the type of dancing northern lights known as discrete aurora.

It builds on work by Nielsen and others.

“We didn’t have the observational capabilities or the computer modeling capabilities that we have now,” Nielsen said of early experiments. “So there were a lot of things that we couldn’t observe.”

“Peter and I talked about KiNET-X when he wrote his thesis, and it was quite clear that we needed a lot more computer power than we had when he graduated,” Nielsen said. “But now we have it, and we also have much better optical imagers.”

Nielsen’s body of aurora work is extensive, so it shouldn’t be a surprise that two of his former students are now working at ������ not far from their long-ago adviser.

Nielsen is recognized for his work studying the upper atmosphere and the physics of the aurora, including He has and has collaborated on  numerous barium-release experiments that seek to understand the workings of the northern and southern lights.

He also provided optical observations for the Geophysical Institute on a 1990 NASA-Defense Department mission called the , or CRRES. The aim was to study Earth’s radiation belts and the space environment under both natural and artificially induced conditions.

Hampton assisted in those observations. Delamere later analyzed the results for his 1998 Ph.D. thesis.

The CRRES satellite carried canisters containing barium and lithium compounds, which were released into Earth’s magnetosphere. This allowed scientists to study plasma dynamics, magnetic field interactions and the effects of charged particle movement in space.

The mission also included several sounding rocket launches and associated ground and airborne observations. The launches performed chemical release experiments in the ionosphere and magnetosphere to complement the satellite’s on chemical releases and observations.

Nielsen was also involved in experiments to understand critical ionization velocity, or CIV, and has authored or co-authored nearly 20 papers on the subject. CIV proposes that a neutral gas becomes ionized if it moves through a magnetized plasma at or above a certain speed. The idea has not yet been conclusively proved.

It’s a topic Hampton knows well. He wrote about CIV for his Ph.D. thesis.

Nielsen said there was plenty of rocket research back in those years, along with opportunity for young space physicists such as his two graduate students.

“We had a lot of different programs, and we employed whoever was available to go into the field,” he said. “It’s fun to be out in the field and do all of these experiments. It’s not fun to sit for nine months and write a thesis.”

Nielsen, who began his time at the Geophysical Institute in 1967, started his aurora work by using television cameras to record the activity. He then turned to the behavioral connection between the northern aurora and the southern aurora.

“We were flying airplanes over Alaska and south of New Zealand to look at how the aurora looked north and south,” he said. “We found that when you had an arc up here, then you had an arc down there, and they were moving synchronously.”

Results from those 1967, 1968 and 1970 flights are detailed in the major , with co-authors Gene Wescott and Neil Davis from the Geophysical Institute and Bob Peterson from Los Alamos National Laboratory.

Nielsen said science has changed markedly since then.

“The whole field now has really turned upside down. Back in the 1970s and ’80s we were using theory to explain experiment results,” he said. “But now computer power has become so sophisticated that it’s the other way around: We’re using experiments to verify theories.”

Of the nine years working with Nielsen to earn his master’s and Ph.D. degrees, Hampton said, “I was doing lots of experimentation, with lots of trips to different places. I was capable of doing optical observations, and so I got to do several different missions.”

“I didn’t know much about space physics to begin with, and Hans offered instruction and the ways of doing or understanding space physics,” he said.

“He was also an expert, along with [geophysics professor] Tom Hallinan, in optical observations,” he said. “Hans was key in teaching me about how bright and how much signal you’re going to get from a certain aurora type. He had lots of experience doing that.”

“He gave me a lot of room to do what I was interested in doing — within constraints.”

Delamere had Nielsen as his Ph.D. adviser from 1991-1998. It was on a summer National Science Foundation program for undergraduates in 1990 that Delamere came to Fairbanks and had Neilsen as his mentor.

Nielsen convinced him to pursue a Ph.D. at ������.

“Hans, first and foremost, exudes enthusiasm. That’s contagious,” Delamere said. “What impressed me most was how hardworking he was.

“Back in the ’90s as an undergraduate, I was so impressed with how unbelievably energetic and passionate everybody was toward their research,” he said. “Hans was a really great role model for a young scientist.”

They both agree that working with Nielsen provided valuable research experience.

“I was a student of the classroom,” Delamere said. “Research was something new to me, where you can start to push boundaries. 

“That’s why it’s so important for undergraduates to have research experiences like that,” he said. “You suddenly discover that the answers aren’t necessarily in the textbooks, and you’re pushing frontiers.”

Today, you can usually find Nielsen in the Geophysical Institute’s Elvey Building, continuing his work on sprites — the large, brief and colorful flashes of light triggered by intense lightning strikes from an underlying storm.

“As in so many scientific endeavors, you start by addressing one problem and get an answer, but in the process 10 other questions turn up,” he said.

How does he feel about inspiring two of his students to continue the work he started so long ago?

“Well, I’m pleased about that, of course,” he said. “They left and then we hired them back because both of them did very, very good work.”

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Rod Boyce is a public information officer and science communicator with the ������ Geophysical Institute.