Astronomers have identified a new type of sugar in the vast clouds of gas and dust between stars, adding a fresh clue to the puzzle of how life emerged on Earth. The molecule, erythrulose, is known on Earth for its presence in raspberries and as a component of self-tanning products, but its detection in the interstellar medium marks a significant step in understanding prebiotic chemistry.
Using two dish-shaped radio telescopes in Spain, researchers from the Centre for Astrobiology in Madrid collected data from a large gas cloud near the centre of the Milky Way. By comparing the telescope signals with laboratory samples, they confirmed the presence of gaseous erythrulose. The findings were published Monday in the journal Nature Astronomy.
Why Sugars Matter for the Origin of Life
Sugars are far more than sweeteners. They fuel cellular metabolism and form the backbone of DNA and RNA, making them essential for life as we know it. Understanding how these molecules form in space helps scientists answer a fundamental question: did the building blocks of life arrive on Earth via comets or asteroids, or were they already present in the primordial material that formed our solar system?
The newly detected sugar is not itself a direct ingredient for life, but it can easily convert into a form thought to be crucial for kick-starting biological processes. It is also one of the most complex sugars ever found in space, according to Erika Hamden, an astrophysicist at the University of Arizona who was not involved in the study. She described it as “a pristine example of the stuff that’s just floating out in the galaxy.”
This discovery lends weight to the latter theory—that key organic compounds were already present in the solar nebula. “Finding them in one location suggests they are likely hiding in distant corners of the galaxy alongside other important molecules,” said lead author Izaskun Jiménez-Serra, an astrophysicist at the Centre for Astrobiology.
Previous research has uncovered other sugars in space. About 25 years ago, astronomers detected a cousin of table sugar near the galactic centre. More recently, black grains retrieved from asteroid Bennu by NASA’s Osiris-Rex mission yielded other sugars, including a key DNA component. The region where erythrulose was found is crossed by NASA’s twin Voyager probes, the farthest human-made objects from Earth.
The European angle is clear: the observations relied on Spanish radio telescopes, and the research team is based at a Spanish institute. This work builds on Europe’s growing role in astrobiology and space chemistry, complementing missions like the European Space Agency’s Rosetta, which studied comet 67P/Churyumov–Gerasimenko, and the upcoming JUICE mission to Jupiter’s icy moons. The findings also resonate with broader European efforts to understand the origins of life, such as the Greek launch of an optical microsatellite to monitor space debris and Earth observation, which underscores the continent’s expanding space infrastructure.
Jiménez-Serra and her team now plan to search for more sugars in different interstellar clouds and investigate how these molecules convert between forms. The presence of erythrulose in one cloud suggests that similar chemistry may be widespread, potentially making the galaxy richer in organic compounds than previously assumed.
For now, the discovery adds a sweet note to our understanding of the cosmos—and a compelling piece of evidence that the ingredients for life may have been baked into the universe from the start.
