For the first time, astrobiologists have positively identified something sweet in outer space. According to a study published today in the journal Nature AstronomyA team successfully identified a type of sugar called erythrulose within a molecular cloud near the center of the Milky Way. Here on Earth, the four-carbon compound is most commonly found in sunless tanning creams and raspberries.

Life as we know it is based on sugars. Biomolecules are an integral part of metabolic processes and at the same time serve as the basis for both DNA and RNA. But despite their importance, evolutionary biologists still aren’t quite sure how the first sugars developed on Earth. Experiments indicate that the prebiotic conditions on the planet billions of years ago simply did not offer the conditions necessary to form sufficient quantities of molecules. However, astronomers have Sugars previously detected as glucose and ribose within fragments of asteroids and meteorites, suggesting that life on Earth may have received a sweet boost from deep space.

For this new study, the researchers conducted a cosmic spectroscopic survey using a pair of highly sensitive telescopes at the Institute for Radio Astronomy in the Millimeter Range (IRAM) near Grenoble, France. After analyzing a region near the gas cloud called G+0.693-0.027 (located about 27,000 light years from Earth), the team identified 12 spectral lines that matched previously measured erythrulose samples. They also measured at least eight times more erythrulose than similar three-carbon sugars in the cloud, which did not include any of the latter variants. Study co-author Izaskun Jiménez-Serra, an astrophysicist at the Center for Astrobiology (CAB) in Spain, called her team’s discoveries completely unexpected.

“The prevailing view in astrochemistry is that interstellar molecules increase in size by the sequential addition of carbon atoms,” he explained in a statement.

Following additional research by chemists at the University of Extremadura (Spain) and Radboud University (The Netherlands), the team determined that erythrulose is capable of forming within interstellar ice particles from simpler alcohols and other molecules. In fact, there is so much erythrulose within G+0.693−0.027 that scientists estimated that between 0.5 and 55 million tons of sugar may have landed on Earth between 4.1 and 3.8 billion years ago, during a formative cosmic era known as the Late Heavy Bombardment. This would have been more than enough to aid in the development of the planet’s first replication and the metabolic processes that ultimately led to life.

“The detection of erythrulose is very exciting because it opens the possibility of discovering in space other sugars such as ribose, which is part of RNA, and other molecules important for the origin of life,” added the co-author of the study and CAB astrobiologist, Carlos Briones.

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