From a small Croatian village to NASA: Following the sun’s most powerful storms

Center: Goddard Space Flight Center

When most people hear the word “corona,” they are likely to think of summer and a cold beer. Veronika Jercic, Ph.D., NASA Postdoctoral Program (NPP) Fellow, thinks about the Sun.

The corona is the Sun’s outer atmosphere, a turbulent region where enormous structures of plasma, known as prominences or filaments, can erupt with enough force to send billions of tons of charged particles racing toward Earth.

“They’re like clouds on the sun,” Jercic said. “Unlike the clouds on Earth, they are much denser, much heavier and colder than the corona in which they are situated.”

Those “clouds” are the focus of Jercic’s research at NASA’s Goddard Space Flight Center, where she is in the second year of her fellowship. The NASA NPP program is administered by ORAU.

While her work explores some of the Sun’s most fascinating physics, its implications reach all the way to Earth, and can profoundly affect satellites, communications systems, power grids and even one of nature’s most spectacular light shows, the Northern Lights.

“When these prominences erupt, they expel a huge mass of particles and energy into interplanetary space,” Jercic said. “This has direct consequences for Earth and for our technologically dependent society.”

While solar prominences are like solar flares, there are distinct differences. Solar flares release radiation that reaches Earth at the speed of light. Prominence eruptions, however, hurl massive clouds of charged particles through space over time. Prominences also move more slowly, traveling hundreds of thousands of kilometers per second. While these particles take longer to arrive, they can have significant effects once they interact with Earth’s magnetic field.

Sometimes those effects are surprisingly beautiful.

“If the particles are directed toward Earth and the conditions are favorable, you get the Northern Lights,” Jercic said.

Solar prominence events last fall and earlier this year produced auroras visible far beyond their usual range, allowing people across much of the United States to witness colorful skies typically reserved for higher latitudes.

A journey built one step at a time

Looking at Jercic’s career today, it would be easy to assume she always envisioned working at NASA.

She didn’t.

Growing up in a small village in Croatia, Jercic loved mathematics and physics. The possibility of conducting research at one of the world’s premier space agencies never crossed her mind.

“I never even dreamt of coming to NASA,” she said. “I didn’t even think it was a possibility.”

Her path toward a career in science began with studying earthquakes through seismology and solid Earth physics. During her master’s program, she took a chance on an internship in Austria that examined how the Sun influences Earth. That experience introduced her to solar physics and ultimately led to doctoral studies in Belgium, where she investigated how solar prominences vibrate, a process called oscillation.

The connection between earthquakes and the Sun turned out to be more natural than it first appeared.

“Earthquakes are basically oscillations in the Earth’s crust,” she said. “Solar prominences are oscillations on the Sun.”

Following four years of doctoral research, Jercic applied to the NASA Postdoctoral Program as an exercise in gaining experience.

“When I was applying, I thought, ‘This is just a learning experience. I will never get this,’” she recalled with a laugh. Then she got the fellowship.

Embracing the unknown

While scientific challenges have certainly shaped her career, Jercic says her greatest obstacles often came from stepping into unfamiliar environments.

Leaving a small Croatian village to study abroad meant moving to countries where she knew no one, navigating new cultures and learning new languages.

“It was scary,” she said. “I’ve never been outside my country. I don’t know anyone. I don’t speak the language.”

Rather than allowing uncertainty to stop her, she adopted a simple philosophy: try anyway.

“You shouldn’t be afraid to try new things,” she said. “Going into the unknown can turn out to be a good thing.”

That mindset also helped her overcome educational gaps. Coming from a small community meant fewer specialized science opportunities than students from larger cities often enjoyed, requiring extra work to catch up when she entered university.

Persistence mattered more than perfect preparation, she said.

The power of mentorship

Throughout her academic journey, whether she was at home in Croatia, studying in Austria or Belgium, and now serving as a NASA Postdoctoral Fellow, Jercic credits mentors for helping her develop both as a scientist and as a researcher.

Her professors encouraged her curiosity. Internship supervisors showed her that science could be collaborative and enjoyable. Her doctoral advisor challenged her while giving her room to make mistakes and learn independently.

Now at NASA Goddard, Jercic’s current mentor has continued that tradition.

“I knew she was a good scientist,” Jercic said of her supervisor, Therese Kucera, Ph.D. “But that’s not the only thing you need to be a good supervisor and mentor.”

Rather, Jercic said Kucera creates and fosters a supportive environment where Jercic can continue growing as a researcher and collaborate with others. For Jercic, one of the greatest strengths of the NASA Postdoctoral Program is the opportunity to collaborate across disciplines and institutions.

She has expanded her scientific interests while building an international network of collaborators.

“I really love to collaborate with people,” Jercic said. “Not just be with my head in my own problems but talk to people about other problems.”

Traveling to scientific conferences has become another valuable part of the experience, allowing her to exchange ideas, receive feedback and continually improve her research.

Advice for future scientists

Like many successful researchers, Jercic acknowledges that she wrestles with uncertainty when considering future opportunities.

The difference, she says, is refusing to let those doubts make decisions for her.

Her advice to students and early-career scientists is straightforward: “Don’t be afraid to try new things, even if you think you’re not good enough. Don’t let those thoughts scare you.”

It’s advice that reflects her own journey, and one that demonstrates how careers in science are often built through curiosity and courage rather than through certainty. After all, as her own career illustrates, sometimes the biggest opportunities begin by simply deciding to see what happens next.