Astronomers have detected erythrulose — a sugar found in raspberries, kiwi, and many red fruits — in interstellar space for the very first time, marking a major milestone in astrochemistry and the search for life's cosmic origins.

The discovery was made by an international team led by Dr. Izaskun Jiménez-Serra of the Centro de Astrobiología (CAB) in Spain, using the Yebes 40-meter radio telescope in Guadalajara and the IRAM 30-meter telescope in Pico Veleta. Their findings were published in Nature Astronomy.

The sugar was identified in the molecular cloud G+0.693−0.027, a dense region near the center of the Milky Way. Erythrulose is a four-carbon ketose (a type of monosaccharide), and it represents the first true sugar ever directly identified in the interstellar medium.

While simpler sugars like glycolaldehyde (a two-carbon sugar) had been detected before, erythrulose is significantly more complex. Its discovery in a harsh, low-metallicity environment suggests that complex organic molecules can form efficiently on the surface of icy dust grains in space — even in regions far less chemically enriched than our own solar system.

"This detection shows that the chemical building blocks of life can be assembled in space under conditions that were previously thought to be unfavorable," said Jiménez-Serra. "Erythrulose is a chiral molecule, meaning it has left- and right-handed versions — a property essential to the biochemistry of life on Earth."

Chirality is a crucial clue for origin-of-life research. Most biological molecules on Earth exhibit "homochirality" — for example, sugars in DNA and RNA are exclusively right-handed. Finding chiral sugars in space raises tantalizing questions about whether the handedness of life's molecules was seeded by interstellar chemistry.

The researchers also showed through modeling that erythrulose forms efficiently on dust grains coated with ice, driven by ultraviolet radiation from nearby stars. This mechanism could operate in molecular clouds throughout the galaxy, implying that the raw ingredients for life may be widespread.

"Every raspberry contains this molecule," the team noted. "Now we know the cosmos does too."

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