Image Courtesy: ESA
Astronomers have identified a naturally occurring sugar in a cloud of gas and dust near the center of the Milky Way, marking the first confirmed detection of a sugar molecule in interstellar space. The discovery strengthens the idea that some of life’s essential chemical building blocks may have formed long before planets like Earth existed.
The international research team, led by scientists at Spain’s Centre for Astrobiology, detected the four-carbon sugar erythrulose in the molecular cloud G+0.693?0.027 using radio telescopes at the Yebes Observatory and the Institute for Radio Astronomy in the Millimetre Range (IRAM). The findings, published in Nature Astronomy, suggest that relatively complex organic molecules can form in the space between stars.
Researchers identified the sugar by matching its unique molecular signature in radio wave observations with laboratory measurements. They had initially searched for simpler three-carbon sugars but instead found erythrulose, a more complex molecule. Sugars are essential to life on Earth, serving as energy sources and forming structural components of DNA and RNA.
Lead author Izaskun Jiménez-Serra said the finding was unexpected because scientists have generally believed interstellar molecules become more complex through the gradual addition of single carbon atoms. Instead, the discovery suggests that relatively complex sugars can already be synthesized in interstellar space before stars and planets are formed.
The study also indicates that erythrulose likely forms on icy dust grains from simpler molecules before becoming part of increasingly complex chemical systems. More than 340 molecules have previously been detected in interstellar space, but this is the first confirmed sugar.
The discovery also supports earlier evidence that sugars found in meteorites and asteroid samples, including material collected from asteroid Bennu, may have originated in space. Scientists believe such compounds could have been delivered to the early Earth by asteroids and comets, potentially contributing ingredients needed for the emergence of life.
Although the exact origins of life remain unknown, researchers say the detection raises hopes of finding even more biologically important molecules in space, including ribose, the sugar that forms a key part of RNA. If confirmed in future observations, such discoveries could provide valuable clues about how the chemical foundations of life spread throughout the universe.
