His moment in the Sun

Cohen, who received his Ph.D. in space physics from UNH, is the deputy chief scientist of the Space Exploration Sector at the Johns Hopkins Applied Physics Laboratory (APL), where he’s worked since he left UNH.

And as our nation turns its gaze to the sun (safely, we hope) to witness a total eclipse, watch the Parker Solar Probe spacecraft get closer than ever to the sun or celebrate NASA’s Heliophysics Big Year, Cohen is seemingly everywhere: presenting at scientific meetings, quoted in the Wall Street Journal, meeting with policymakers, even showing up in social media videos to explain concepts like space weather.
That’s because the sun is in the middle of a cycle of heightened activity called the solar maximum, giving Cohen and heliophysics — the study of the sun and how it interacts with Earth and the rest of our solar system — a moment in, well, the sun.
“We’re in a period of a lot of solar activity, when there’s more solar flares and coronal mass ejections,” says Cohen, noting this solar maximum is more active than any we’ve seen in decades. “For us scientists that’s really exciting, because there’s more activity for us to explore.”
But as our society increasingly relies on technology like satellites and our appetite for human space exploration increases, what happens on the sun doesn’t stay on the sun, bringing heliophysics down to Earth with real-world implications.
“We have more and more satellites than ever, and we have a lot more infrastructure and a lot more susceptibility to solar activity than we did 20 years ago,” says Cohen, noting that our beloved cell phones are among the many essential technologies vulnerable to solar activity. “And if we want to send astronauts beyond this safe cocoon of Earth’s magnetic field to the moon or potentially to Mars, we need to understand the environment that we’re sending them into.”
Cohen credits his UNH advisor, research professor Marc Lessard, for helping launch his career. “I was extremely fortunate to work in his lab on hardware that would fly on rockets to look at the aurora,” he says. “That experience is why I was able to get work at APL.”
Lessard and Harlan Spence, director of UNH’s Institute for the Study of Earth, Oceans and Space, also provided mentorship for the advocacy and leadership work Cohen is undertaking with professional societies like the American Astronomical Society and the American Geophysical Union.
Cohen praises Lessard and his UNH mentors for giving him the leeway to “choose my own adventure,” letting him pursue extracurriculars like serving on the Graduate Student Senate and managing the UNH Observatory, a position he held throughout his time at UNH. He remains close to observatory director John Gianforte.
“He brought a telescope to my wedding so people could look at Saturn during the reception,” he recalls, adding, “It was awesome.”

“MMS is rewriting the textbooks on how we think magnetic reconnection works,” he says of the important universal physical process the quartet of satellites measures.
Cohen is proud to be a part of UNH’s storied space science legacy. “One of the fun things about being in the heliophysics field is UNH has such a long history in space physics, especially for such a small institution,” he says. “It’s one of the premier institutions for heliophysics, and I love being able to connect to that history and to the people who are part of it.”

How Did You Find Your Spark?
When I was a kid, I got a telescope from my aunt and uncle for Christmas one year. I remember taking it out in my front yard on a really cold night and pointing it up and seeing the rings of Saturn for the first time with my own eyes. It was the most amazing thing I’d ever seen. I wrote down my observations in my little marble composition notebook because I was going to be a real scientist.