Sugar Linked to Life's Origins Found in Milky Way Cloud

Scientists found erythrulose, a sugar also present in raspberries, inside a gas cloud near the center of the Milky Way. The discovery marks the first time this specific sugar has been detected outside the solar system, according to a study published Monday in the journal Nature Astronomy.

Erythrulose contains four carbon atoms. Spanish researchers confirmed its presence using the Yebes 40-meter telescope and the IRAM 30-meter telescope, both in Spain.

Sugars are a basic building block for life alongside water and carbon. The finding suggests erythrulose could have formed in interstellar space before being incorporated into young rocky planets like Earth, rather than developing later on the planet's surface. Lab experiments had indicated that not enough of the sugar could have formed on pre-life Earth.

"We were able to achieve this detection thanks to the combination of exceptionally sensitive observations, extensive frequency coverage and highly accurate laboratory spectroscopic data," said Dr. Izaskun Jiménez-Serra, a co-author and staff researcher at the Spanish National Research Council. "In addition, our astronomical target is one of the richest chemical inventories in the galaxy, which enhances the probabilities of detection."

Jiménez-Serra called erythrulose "particularly relevant for the field of origins of life."

The sugar changes the composition of threose, another sugar, which may be part of how nucleic acids that became RNA and DNA first formed, researchers said. Other sugars including ribose and glucose had previously been found inside meteorites and asteroids.

"The findings suggest that erythrulose can be made from simpler molecules on dust grains in space, and may then become part of more complex chemical systems," the researchers said.