Astronomers detect first 'true sugar' molecule in interstellar space

Astronomers have detected a four-carbon sugar molecule called erythrulose in a cloud of gas and dust near the centre of the Milky Way — the first "true sugar" ever identified in interstellar space, according to a study published in the journal Nature Astronomy (https://www.nature.com/articles/d41586-026-02173-5).

The team, led by Izaskun Jiménez-Serra of the Spanish National Research Council in Madrid, found the molecule's distinctive spectroscopic "fingerprint" in observations from Spain's Yebes 40-metre and IRAM 30-metre radio telescopes. The reference data were supplied by physical chemist Emilio Cocinero of the University of the Basque Country, who shared erythrulose's wavelength signature so the team could search for it in their sky surveys (https://www.nature.com/articles/d41586-026-02173-5).

The find could help clarify how life on Earth began. A five-carbon sugar, ribose, was previously found in billion-year-old meteorite samples, suggesting space rocks may have delivered sugars to the early Earth. In 2000, astronomers detected glycolaldehyde — sometimes called the simplest sugar — in interstellar space, but experts note it is not formally a sugar; true sugars require a backbone of at least three carbon atoms (https://www.nature.com/articles/d41586-026-02173-5).

"It is an incredibly exciting result," said Brett McGuire, an astrochemist at the Massachusetts Institute of Technology. "Astronomers have, for a very long time, been pushing to detect sugars in space." The detection of a true sugar strengthens the case that the chemical building blocks of life can form in the cold environments between stars, before being delivered to planets like Earth (https://www.nature.com/articles/d41586-026-02173-5).

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