UNH Today

The northern lights — aurora borealis — put on quite a show in 2024. While typically visible across high-latitude regions like Iceland and Canada, last year brought an unexpected twist with the lights appearing as far south as Florida. In May, the strongest solar storm in 21 years lit up the sky and in October, the stunning colors were visible once again across much of the United States.

Nada AlHaddad and Noé Lugaz, research professors in the Space Science Center of UNH’s Institute for the Study of Earth, Oceans and Space (EOS), study coronal mass ejections (CMEs), the solar phenomena that can result in northern lights.

What are northern lights?

AlHaddad: Northern lights are a flow of charged particles from the sun coming into Earth's atmosphere and streaming along the Earth's magnetic field lines.

This happens when the sun releases what we call coronal mass ejections, charged plasma with magnetic field coming toward Earth. Electrons and protons coming from the sun interact with gases in Earth's atmosphere, namely oxygen and nitrogen. Oxygen gives us red and green hues, and photons emitted by nitrogen particles give us more blue and dark red or purple-ish hues.

Why have the northern lights become more visible lately?

Lugaz: The sun was more active in 2024 than any year since 2003 or 2004. We’re at the maximum point of the 11-year solar cycle, and the last maximum solar cycle, which was around 2012 to 2014, was relatively weak. You have to go back 20 years to when you could see auroras in the central U.S., or even Florida.

What's the best way to see the northern lights?

AlHaddad: The northern lights typically show better around March or September. These are the best times to see them due to a special effect when Earth's magnetic field aligns with the sun's magnetic field, allowing more particles to flow to Earth. Also, around the equinoxes, we get longer nights. Obviously, northern lights are dim, so you need dark skies.

Do you have any predictions about how the northern lights may change in the coming years?

Lugaz: Some of the largest eruptions tend to happen in the declining phase of the solar cycle, so just slightly after the solar maximum. We probably are likely to see more northern lights in the next, let's say, two years.

Historically, some of the largest eruptions have happened within one to three years after the solar maximum. Thus, 2025 and 2026 will likely still be good years to see northern lights. Then after that, we probably will have to wait another cycle — another 10 years — if you want to see the northern lights in the continental U.S.

AlHaddad: We typically look at the previous solar cycles to try and predict how the next cycle is going to be. However, since this current cycle was predicted to be a weak one but wasn't, it's still an active area of research. There is only so much prediction we can make.

How does UNH work with NASA and NOAA to study the northern lights?

AlHaddad: Our group, which is the Coronal Mass Ejections (CME) group — probably the only CME-specialized group in the whole country — conducts substantial research on this matter.

Lugaz: One cool thing about the UNH Space Science Center is there's research going on from the sun to Earth’s atmosphere and everything in-between.

For example, UNH worked on a mission from NASA called STEREO that was launched in 2006 to measure solar wind. During the coronal eruption event in May, STEREO happened to be a bit closer to the sun than Earth and we were able to measure the eruption that would be impacting Earth about two or three hours before it happened.

This mission was launched 18 years ago but happened to be in in the right place at the right time.

What is your experience with the northern lights — from a professional and personal perspective?

Lugaz: We're both foreign-born and U.S.-educated. I went to the University of Michigan and just ended up going into a department that does space science. Once I got there, I just thought it was fascinating. I think I only saw the northern lights once. Understanding the cause at the sun is really what interests me.

AlHaddad: When I was an undergrad, I didn't realize that the sun was an active area of research. I knew that the sun is a star, but it's the sun: you don't think of it as another star, really.

If we want to talk about nature's phenomena or astronomical phenomena, there’s a lot to be fascinated by. But northern lights are a direct interaction between a celestial object and Earth. The sun is sending particles towards us, and we see them, and it's a breathtaking phenomenon. It's like a conversation between the sun and Earth. So that's very, very beautiful.