A type of sugar found naturally in raspberries has been detected near the centre of the Milky Way, marking the first time the molecule has been identified beyond the Solar System. The discovery has strengthened the idea that some of the essential ingredients for life may be more common across the universe than previously thought.
Researchers identified the sugar, called erythrulose, in a giant cloud of gas and dust known as G+0.693-0.027, close to the Milky Way's centre. The findings suggest that complex organic molecules capable of supporting prebiotic chemistry may have formed in interstellar space long before planets came into existence.
The study was published in the journal Nature Astronomy.
What is erythrulose?
Erythrulose is a naturally occurring sugar made up of four carbon atoms. It is found in fruits such as raspberries and plays an important role in chemical processes linked to the origins of life.
Unlike sugars that are directly involved in modern biological systems, erythrulose is believed to influence the formation of other important sugars associated with early genetic molecules.
Its detection beyond the Solar System marks a significant milestone in astrochemistry.
How did scientists detect the sugar?
The research team identified erythrulose using the Yebes 40-metre Radio Telescope and the IRAM 30-metre Radio Telescope in Spain.
Scientists confirmed the molecule by matching signals detected in space with laboratory measurements, providing strong evidence that erythrulose exists naturally within the interstellar medium.
The sugar was discovered inside the molecular cloud G+0.693-0.027, a region already known for containing a rich variety of complex organic molecules.
Why is the discovery important?
The discovery provides fresh evidence that the chemical ingredients required for life may form in space before planets are created.
Previous studies have identified molecules such as water, ribose and glucose in meteorites and asteroid samples. However, scientists had struggled to explain how erythrulose could have formed on the early Earth because laboratory experiments produced only very small amounts of the sugar under prebiotic conditions.
Finding the molecule in interstellar space offers a possible explanation.
As quoted by Live Science, researcher Víctor M. Rivilla said the discovery is particularly significant for studies into the origins of life because erythrulose can alter the structure of another sugar known as threose.
"Finding erythrulose is particularly relevant for the field of origins of life."
Scientists believe threose may have been an important precursor to the first nucleic acids that eventually evolved into RNA and DNA.
Sugar molecules may have reached Earth before the planet formed
The researchers suggest that erythrulose could have formed on tiny dust grains floating through interstellar space before becoming incorporated into young planets during their formation.
This means that sugars such as ribose, glucose and erythrulose may already have existed as part of Earth's chemical inventory long before life emerged.
The study also indicates that these molecules can be produced from simpler compounds under conditions found in space, supporting theories that prebiotic chemistry begins well before planets develop.
Discovery adds to growing evidence of life's building blocks in space
Scientists have previously detected biologically important sugars in meteorites and asteroid material.
Earlier this year, samples collected from asteroid Bennu by NASA's OSIRIS-REx mission were found to contain ribose and glucose, further strengthening the theory that many of the chemical ingredients necessary for life are widespread throughout the Solar System.
The latest discovery extends that evidence beyond our planetary neighbourhood and into interstellar space.
What researchers hope to find next
Scientists now plan to search for even more complex sugars and molecules directly linked to RNA formation.
As quoted by Live Science, researcher Sergio Jiménez-Serra said future observations will focus on understanding how far prebiotic chemistry can develop before planets are formed.
"One of the most exciting next steps is to search for even more complex sugars and for molecules that are direct precursors of RNA, and other biologically important compounds. We want to understand how far prebiotic chemistry can progress before planets are even formed, and what chemical inventory young planetary systems inherit from interstellar space."
The discovery of erythrulose near the centre of the Milky Way adds another important piece to the puzzle of how life may begin.
Rather than forming only on planets, some of life's essential chemical ingredients may already exist in interstellar clouds, ready to become part of newly forming planetary systems. If confirmed through further studies, the finding could reshape scientists' understanding of how the building blocks of life are distributed across the universe.
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