Astronomers have made a groundbreaking discovery of erythroulose, a tetracarbon sugar primarily found in raspberries and sunscreen cosmetics, in the molecular cloud G+0.693-0.027 using the Ieves 40-meter and IRAM 30-meter radio telescopes.
This composite image showcases the central region of the Milky Way and the location of molecular cloud G+0.693-0.027. Image credit: Ashley Barnes / Izaskun Jiménez-Serra / Juan García de la Concepción.
Sugars play a vital role in life, forming the backbone of DNA and RNA while also serving as metabolic fuel. However, scientists have long debated how sugars could have formed in significant quantities on early Earth.
Laboratories that simulate prebiotic conditions typically yield only minimal amounts of sugar.
The detection of ribose and glucose in samples from meteorites and the asteroid Bennu has led to speculation that some of Earth’s sugars may have extraterrestrial origins.
Prior to this finding, actual sugars had never been identified in the interstellar medium.
“Sugars are critical biomolecules that act as metabolic fuels, components of nucleic acids, and structural or energy storage polymers,” stated Izaskun Jiménez-Serra, PhD, from CSIC-INTA and colleagues.
“A key question in the study of the origin of life is how monosaccharides formed on early Earth, as experiments under prebiotic conditions have produced insufficient concentrations.”
Astronomers utilized the Ieves 40-meter and the IRAM 30-meter radio telescopes to investigate the molecular cloud G+0.693−0.027, a chemically rich region located approximately 8,200 parsecs (26,745 light-years) from Earth.
They detected 12 sets of radio emission lines corresponding to the predicted spectral fingerprint of erythroulose, with the chemical formula C4H8O4.
“Erythroulose, consisting of 14 atoms, is the largest acyclic molecule ever found in the interstellar medium and the first identified molecule containing four oxygen atoms,” the researchers noted.
This detection marks the first sugar discovery and the second chiral molecule observed in the interstellar medium.
“Its presence not only provides direct evidence that complex chiral species can form under interstellar conditions, but also elevates the level of interstellar chemical complexity, suggesting that other prebiotic and potentially chiral molecules could form and endure in the harsh conditions of the interstellar medium.”
Researchers found that erythroulose was at least eight times more abundant than tricarbon sugars like glyceraldehyde and dihydroxyacetone, which were not detected in the same clouds, despite the survey’s sensitivity.
This discovery indicates that erythroulose might be synthesized from simpler molecules on cosmic dust grains, subsequently integrating into more complex chemical systems.
“This unexpected discovery challenges the prevailing view in astrochemistry that interstellar molecules grow by the sequential addition of carbon atoms,” Jiménez-Serra emphasized.
Dr. Carlos Briones, also from CSIC-INTA, added, “The detection of erythroulose opens new avenues for discovering other sugars in space, such as ribose, a component of RNA, and other crucial compounds for the origin of life.”
This groundbreaking finding is detailed in the following article: paper published in today’s issue of Nature Astronomy.
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I. Jimenez-Serra et al. Tetracarbon sugar detected in interstellar space. Nat Astron, published online on July 13, 2026. doi: 10.1038/s41550-026-02905-7
Source: www.sci.news
