Astronomers Detect Sugar Molecule in Interstellar Cloud

Astronomers detected erythrulose, a monosaccharide with four carbon atoms, in molecular cloud G+0.693−0.027 located near the Milky Way's center. The study, published this week in Nature Astronomy, used data from two radio telescopes in Spain to identify the molecule's microwave signature.

One telescope is at the Yebes Observatory northeast of Madrid; the other is at the Institute for Radio Astronomy in the Millimeter Range near a Sierra Nevada ski resort.

The cloud is one of the richest molecular regions in the galaxy. Collisions with another cloud have produced alcohols, aldehydes, urea, ethanolamine, hydroxylamine, and dozens of other complex organic molecules. Researchers led by Izaskun Jiménez Serra analyzed the data to confirm erythrulose's presence.

The molecule belongs to the ketose family and occurs on Earth in raspberries and some tanning lotions.

2025, scientists confirmed ribose and other monosaccharides in samples from asteroid Bennu. The new finding adds a ketose sugar detected in the interstellar medium rather than on a solar-system body. Jesús R. Flores, a professor at the University of Vigo who was not involved in the study, said the detection shows monosaccharides can form in the interstellar medium.

He noted that erythrulose is the first true saccharide identified there. The presence of the sugar does not indicate extraterrestrial life or explain the origin of life on Earth. It demonstrates that chemical building blocks associated with prebiotic chemistry can form in space.