A Piece of the Origin of Life Discovered in the Heart of the Galaxy

Astronomers have identified for the first time a true sugar in interstellar space. This is erythritol, a four-carbon atom molecule found on Earth in raspberries and self-tanning products, discovered in a gas cloud near the center of the Milky Way.

The discovery is credited to an international team led by Izaskun Jiménez-Serra from the Spanish Center for Astrobiology, with contributions from researchers at the University of Extremadura and Radboud University in the Netherlands. The data comes from two radio telescopes installed in Spain, the 40-meter Yebes and the 30-meter IRAM, focused on the molecular cloud G+0.693-0.027. By comparing the collected signals with lab spectra, scientists identified 12 spectral lines matching the chemical signature of the sugar.

Erythritol is not essential to life itself, but it easily converts into a form considered crucial for triggering its origin on Earth. It is also one of the most complex sugary compounds ever detected outside the Solar System, according to astrophysicist Erika Hamden from the University of Arizona.

A Prebiotic Chemistry More Widespread than Expected

This is not the first time scientists have intercepted sugars in deep space. About 25 years ago, a relative of table sugar was found near the galactic center, while black grains collected from the asteroid Bennu by NASA's Osiris-Rex probe had yielded other sugars, including a key ingredient for DNA formation.

However, the most surprising data concerns the formation mechanism. The team observed that erythritol is generated within interstellar ices from two-carbon atom alcohols and aldehydes, contrasting with the previously prevailing hypothesis that complex molecules grow by sequential addition of single atoms. The study was published in Nature Astronomy on Monday, July 13.

The observed region is also familiar to human exploration: it is the same region traversed by NASA's twin Voyager probes, the artificial objects that have traveled farthest from Earth. This detail makes the idea that the chemical building blocks of life are not exclusive to our planet even more concrete, as they can form anywhere in the galaxy where suitable physical conditions arise.