"New horizons to explore."

That's one of the first lyrics in the song, "New Horizons," recently release by the guitarist and song composer for the legendary rock band Queen, Brian May.

It's also could be a descriptor for the rockstar's career.

In addition to a history-making career with the band Queen, May is also an astrophysicist.

May, 71, has contributed to the production of or performed on recordings that have sold more than 100 million copies worldwide, according to the band's website. He wrote, among other songs, the hit anthem, "We Will Rock You."

Before he committed to be part of Queen, which formed in 1971, May was studying astrophysics.

"When I was about to finish my thesis, it was just the beginnings of Queen and I had to make that choice. And my choice was made on the assumption that I wasn't very good at physics and I might be quite good at music," May told Time, according to a transcript published Wednesday.

The thesis he had been working on was about dust that collects in the solar system, called "zodiac dust." Over the years, interest in zodiac dust waxed, waned and waxed again, he told Time.

"Suddenly my subject became very in-demand again. I started talking about astronomy again to people who said, 'Why don't you still do it?' I put everything, and I mean everything, on hold for a year. And they put me in a little office in Imperial College [in London] and I got down to it," May told Time.

In 2007, May received his PhD in astrophysics from Imperial College, some 30 years after he began his studies, according to Queen's band's website.

On Monday, May's two worlds officially collided: he released the song "New Horizons" to honor NASA's spacecraft of the same name, which on the first day of the new year, Tuesday, flew past Ultima Thule, the "most distant target in history," according to NASA. (The official video for May's song and lyrics, are included below.)

"New Horizons performed as planned today, conducting the farthest exploration of any world in history — 4 billion miles from the Sun," said the mission's principal investigator Alan Stern, of the Southwest Research Institute in Boulder, Colorado, according to a written statement.

In the early hours of New Year's Day, @NASANewHorizons flew past #UltimaThule, an object located in a region of primordial objects 1 billion miles past Pluto. Join us live from @JHUAPL today at 2pm ET as we explore the latest science from the spacecraft:

May met Stern through a friend, he tells Time, in early 2015.

"He called me about six months ago and said, 'Is there any chance you can make music for the new flyby?' And I kind of very nervously said, 'Okay, let me think about it.' There's not a lot of things that rhyme with Ultima Thule," May joked to Time.

"But I went away and thought about it. And what hit me was how inspiring the whole project was from the point of view of the human spirit of adventure. So that's really what I wrote this song about, as a tribute to the New Horizons team."

Both prongs of May's bifurcated career are extraordinary, but the fact of having multiple professional trajectories in a career is not.

It's hard to know just exactly how many careers workers will have in their lifetimes — the federal government doesn't even try to track such a statistic. "The Bureau of Labor Statistics (BLS) never has attempted to estimate the number of times people change careers in the course of their working lives. The reason we have not produced such estimates is that no consensus has emerged on what constitutes a career change," the federal government's labor department says. But data from career website LinkedIn shows younger workers tend to switch jobs more than their older cohorts in the first decade out of college. "Millennials are job-hopping more than previous generations. Case closed," the 2016 LinkedIn post says.

While switching careers may becoming increasingly common, it's not easy. Even May gets the jitters flexing his astronomy muscles.

"I get to hang out with real astronomers, which is great, but I still have that kind of, what do they call it, impostor syndrome. I'm in this plenary meeting with all the New Horizons people, these teams coming together and I keep thinking to myself, 'Should I really be here? Am I really worthy of being with these guys?'" May told Time.

"So the music helps. Now I have a reason I can hold my head up and say I played a part in this."