Erythrulose Sugar Found in Interstellar Space Near Galactic Center

An international team of astronomers has detected the four‑carbon sugar erythulose in the interstellar medium for the first time. The molecule was identified in the dense molecular cloud G+0.693‑0.027, located about 26 000–27 000 light‑years from Earth toward the centre of the Milky Way. Observations were made with the 40‑metre Yebes radio telescope in Spain and the 30‑metre IRAM telescope in the Sierra Nevada, and the spectral signatures matched laboratory measurements of erythulose.

The discovery, led by Izaskun Jiménez‑Serra of the Centro de Astrobiología and published in Nature Astronomy (13 July 2026), shows that a true sugar—a chiral ketose that on Earth is found in raspberries and used in cosmetics—can form naturally in space. Its abundance appears eight to seventeen times higher than smaller three‑carbon sugars, contrary to previous expectations about interstellar chemistry.

Scientists argue that such molecules could have been incorporated into comets and asteroids and delivered to the early Earth. Estimates suggest 0.5–50 million tonnes of erythulose may have arrived during the Late Heavy Bombardment, potentially providing pre‑biotic building blocks for the first metabolic and genetic systems.