Discovery reveals rapid pathways to complex aromatic molecules in space

A team of researchers led by the University of Hawaiʻi at Mānoa Department of Chemistry has uncovered a faster way large carbon-based molecules may form in space, helping solve a long-standing mystery about how some of the building blocks of the universe grow.

The study, published in Nature Communications in August 2026 and first-authored by chemistry graduate student Shane Goettl, identifies a new chemical process that could explain the rapid formation of polycyclic aromatic hydrocarbons (PAHs)—large molecules made of carbon and hydrogen that are found throughout the universe, from dying stars to clouds of gas between stars.

Scientists have known these molecules are abundant in space, but existing theories could not explain how they formed quickly enough to match what telescopes observe or the material that space missions returned from carbonaceous asteroids such as Ryugu.

Faster chemical process

The research shows that a newly identified chemical reaction can build these complex molecules much faster than previously thought. Rather than adding carbon atoms one at a time, the process allows several new chemical bonds to form in a single step, speeding the growth of larger molecules.

The team demonstrated the process in laboratory experiments that recreated the extremely high temperatures found around aging stars and other energetic environments in space. The reactions produced several large PAHs that had been predicted but were difficult to explain using older models.

The discovery could improve scientists’ understanding of how carbon evolves in the universe and how increasingly complex molecules are created. Those molecules are believed to play an important role in the chemistry of stars, planets and the material that eventually forms solar systems.

“This discovery changes how we think these large carbon molecules are built,” said Ralf I. Kaiser. “For years, we knew they existed in enormous numbers throughout space, but we couldn’t explain how nature produced them so efficiently. We’ve now identified a much faster pathway that helps connect the smallest carbon molecules to the complex structures found across the universe.”

The research was led by UH Mānoa in collaboration with researchers in Taiwan (Agnes Chang) and the synchrotron facility SOLEIL in France (Laurent Nahon).

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Robert Egan

Bachelor’s in mathematical biology, Master’s in creative writing. Well-traveled with unique perspectives on science and language.

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