Scientists at Aarhus University have demonstrated that the building blocks of proteins can form naturally in the harsh conditions of deep space. Through lab simulations of interstellar environments, researchers found that amino acids link into peptides under extreme cold and radiation. This discovery suggests life's chemical ingredients may be more widespread in the universe than previously thought.
In a groundbreaking study, researchers from Aarhus University in Denmark, along with collaborators at a facility in Hungary, have shown that peptides—short chains of amino acids that serve as precursors to proteins—can emerge in the cold, radiation-filled voids between stars. The experiments, detailed in the journal Nature Astronomy in 2026, challenge long-held views that complex organic molecules only assemble closer to planetary formation.
The team, led by Sergio Ioppolo and Alfred Thomas Hopkinson, replicated the conditions of interstellar dust clouds in a specialized chamber. These clouds, located thousands of light-years from Earth, maintain temperatures around -260°C and near-vacuum pressures. By introducing glycine, a simple amino acid, and bombarding it with simulated cosmic rays via an ion accelerator at HUN-REN Atomki, the scientists observed the molecules reacting to produce peptides and water.
"We saw that the glycine molecules started reacting with each other to form peptides and water," Hopkinson noted. "This is a step toward proteins being created on dust particles, the same materials that later form rocky planets."
Previously, experts assumed such clouds could only host basic molecules, with complexity arising later as gases coalesced into stellar disks. Ioppolo highlighted this shift: "We used to think that only very simple molecules could be created in these clouds... But we have shown that this is clearly not the case."
The findings, supported by the Center for Interstellar Catalysis funded by the Danish National Research Foundation, imply that as these dust clouds collapse into stars and planets, they could deliver life's essential components to habitable zones. Co-author Liv Hornekær emphasized the broader potential: "These molecules are some of the key building blocks of life." While proteins are just one piece of the puzzle—others like membranes and nucleobases remain under investigation—the research bolsters prospects for extraterrestrial life by revealing a universal chemical pathway for peptide formation.
