A type of sugar found on Earth in raspberries and self-tanning products, erythrulose, has been detected in the interstellar medium, or the space between stars, according to a study.
On Earth, erythrulose is commonly found in raspberries and sunless tanning cosmetics.
How sugar molecules first formed on Earth is a question scientists have been looking into, because experiments show they do not easily form under early Earth conditions.
However, until now, no sugar had been directly detected in the interstellar medium, the researchers said.
"Interstellar erythrulose could have contributed to the sugar inventory available for early metabolic and replication processes," the authors wrote.
A type of sugar found on Earth in raspberries and self-tanning products, erythrulose, has been detected in the interstellar medium, or the space between stars, according to a study.
Sugars are fundamental to metabolic processes, but in the context of origins of life, a sugar molecule is essential for producing the first nucleic acids, primary forms of which are DNA and RNA.
The findings published in the journal Nature Astronomy indicate that complex, biologically important molecules can form in space and may contribute to the chemical ingredients available for early metabolic and replication processes.
Researchers, including those from the Spanish National Research Council, detected erythrulose, made of four carbon atoms, near the centre of the Milky Way galaxy and towards the molecular cloud named 'G+0.693-0.027'.
They observed the cloud with the Yebes 40-metre (located in Yebes, Spain) and the Institute for Radio Astronomy in the Millimeter Range (IRAM) 30-metre radio telescopes in Spain.
The sugar was identified by matching signals in the data to the pattern for erythrulose measured in the laboratory, finding 12 matching sets.
The team also found that erythrulose is at least eight times more abundant in the gas cloud than similar sugars with three carbon atoms, which were not detected in the same location.
"This finding was unexpected, as the prevailing view in astrochemistry is that interstellar molecules grow in size through the sequential addition of carbon atoms," lead author Izaskun Jimenez Serra from the Spanish Astrobiology Center, Spanish National Research Council, said.
Sugars are important molecules in living systems, helping to provide energy, build important biological structures, and form parts of genetic material. On Earth, erythrulose is commonly found in raspberries and sunless tanning cosmetics.
How sugar molecules first formed on Earth is a question scientists have been looking into, because experiments show they do not easily form under early Earth conditions.
Previous studies show the discovery of ribose and glucose -- sugars essential for life -- in meteorite and asteroid samples, which suggested that some sugars may have come from space. However, until now, no sugar had been directly detected in the interstellar medium, the researchers said.
Amounts of erythrulose measured in the G+0.693-0.027 molecular cloud helped the researchers estimate that between 0.5 and 50 million tonne of the sugar could have reached Earth's surface during the Late Heavy Bombardment, which occurred approximately 4.1 to 3.8 billion years ago.
Therefore, the presence of erythrulose in interstellar space provides an alternative source of sugars that may have contributed to the emergence of the first metabolic and replication processes on the early Earth, the team said.
"Interstellar erythrulose could have contributed to the sugar inventory available for early metabolic and replication processes," the authors wrote.
The findings also suggest that erythrulose can be made from simpler molecules on dust grains in space and may then become part of more complex chemical systems, they said.
Published on July 20, 2026
