Astronomers Detect Four-Carbon Sugar Erythrulose in Interstellar Space

Detection in the G+0.693-0.027 Cloud

The discovery was made by a team of researchers, including scientists from the Spanish National Research Council, who utilized two major radio telescopes in Spain: the 40-meter Yebes telescope and the 30-meter Institute for Radio Astronomy in the Millimeter Range (IRAM) facility. By observing the molecular cloud G+0.693-0.027, located near the heart of the Milky Way, the team identified the chemical signature of erythrulose by matching observed signals against 12 laboratory-measured data sets.

This finding challenges traditional models of astrochemistry. As Dr. Izaskun Jiménez-Serra of Spain’s Centre for Astrobiology noted, the discovery was unexpected because the prevailing view suggests that interstellar molecules typically grow through the sequential addition of single carbon atoms. Instead, the researchers found that erythrulose is at least eight times more abundant in this region than similar three-carbon sugars, which remained undetected in the same cloud.

For more on this story, see Astronomers Detect First Interstellar Sugar in Milky Way Dust Cloud.

Chemical Origins and Prebiotic Implications

The research, published in Nature Astronomy, details how erythrulose likely forms on the surface of microscopic interstellar dust grains. Despite temperatures in the cloud hovering around -250°C, simple organic precursors—specifically glycolaldehyde and ethylene glycol—combine to synthesize the sugar. This mechanism provides a potential explanation for how complex prebiotic molecules are distributed throughout the galaxy.

For scientists studying abiogenesis, the detection provides a missing link. While sugars have previously been identified in meteorites and on the asteroid Nature, this is the first direct detection within the interstellar medium. The ability of these compounds to form in space suggests they could have been delivered to early Earth during the Late Heavy Bombardment, approximately 4.1 to 3.8 billion years ago. Researchers estimate that millions of tonnes of such organic material could have rained down on the planet, potentially seeding the chemical inventories required for early metabolic processes.

Expert Perspectives on the Sugar Inventory

Theguardian of Tohoku University, who has conducted extensive research on sugars found in asteroid samples, emphasized the significance of finding these precursors in space. According to Furukawa, while the process by which planetary environments utilize these molecules remains a subject of ongoing study, the supply of interstellar organics is a critical factor in understanding the emergence of life.

This follows our earlier report, You’ll Never Guess What Tasty Molecule Astronomers Just Detected In Space.

Beyond its role in prebiotic chemistry, erythrulose is a well-known compound on Earth. It is found in trace amounts in raspberries and is commonly used in sunless tanning lotions, where it reacts with amino acids in skin cells to produce brown pigments known as melanoidins. While the presence of this specific sugar in space does not imply the existence of complex biological life in the Milky Way’s center, it confirms that the fundamental building blocks—and the energy sources for early metabolism—are readily available in the cold, vast reaches of the galaxy.