Astronomers Detect Sugar Molecule Erythrulose in Milky Way Molecular Cloud

Discovery	Detection of erythrulose in the interstellar medium
Lead Researcher	Izaskun Jiménez-Serra (Centre for Astrobiology, Spain)
Publication	Nature Astronomy
Location	Molecular cloud G+0.693-0.027 (Milky Way center)

Identification of Erythrulose in the Milky Way Center

Detection of Erythrulose in the G+0.693-0.027 Cloud

Izaskun Jiménez-Serra and the Chemical Factory of Molecular Cloud G+0.693-0.027

Researchers identified the sugar molecule erythrulose within a dense molecular cloud designated G+0.693-0.027, located near the galactic center. To carry out this search, the team used two radio telescopes in Spain to peer into the cloud. The researchers noted that while earlier searches in such highly dense regions struggled to filter out background noise, their approach was “laser-focused,” allowing them to detect the signature of the four-carbon sugar. This discovery was unexpected; the team found almost no signs of sugars made from three carbon atoms, which cuts against the prevailing scientific belief that sugars gradually form by adding one carbon atom at a time. Consequently, the team suspects the four-carbon sugar was formed by the combination of two other organic molecules that each contain a carbon pair.

For more on this story, see Astronomers Detect Complex Erythrulose Sugar Near Milky Way Center.

The team behind the finding, led by Izaskun Jiménez-Serra, an astrochemist at Spain’s Centre for Astrobiology, observed the cloud at temperatures hovering around -250C. According to the researchers, erythrulose forms when two other organic compounds, glycolaldehyde and ethylene glycol—which are abundant in some corners of the cosmos—combine on the surface of microscopic dust grains. These clouds act as a chemical factory, fusing disparate atoms together to form more complex substances. More than 340 molecules have been detected in the interstellar medium to date.

Implications for Prebiotic Chemistry and the Origins of Life

Formation of Ribonucleotides During the Late Heavy Bombardment

The presence of erythrulose is significant for astrobiology because the molecule can form ribonucleotides, the building blocks of RNA. As early life evolved, DNA emerged as a more robust store for genetic code, with RNA serving as the intermediary between genes and the proteins from which life is made. The discovery provides a new perspective on how life might develop on other worlds.

This is the very first sugar to be detected in interstellar space and it is important because it tells us that these sugars are more common than we previously thought, Izaskun Jiménez-Serra stated. It opens the possibility for life to develop on other worlds in a similar fashion to what it did on Earth.

Scientists have long struggled to understand how simple sugars became abundant on Earth, as laboratory studies indicate they would not have formed easily on the young planet. While ribose and glucose have been found on asteroids, and some scientists believe these compounds were brought to Earth by wayward space rocks, this study provides the first direct detection of such a compound in the interstellar medium. The researchers estimate that millions of tonnes of erythrulose could have rained down on Earth when a surge of asteroids and comets battered the planet during the period known as the Late Heavy Bombardment.

This follows our earlier report, Sugar Found at Center of Milky Way: A New Clue to the Origins of Life.

Context and Scientific Precedents

V. M. Rivilla and A. Belloche’s Prior Research on Interstellar Precursors

This discovery follows a long lineage of research into interstellar molecular complexity. M. Rivilla and A. Belloche. The current study in Nature Astronomy builds on this foundation by confirming that the chemical pathways for life’s building blocks extend into the frigid expanse between stars. The discovery does not suggest that the galaxy revolves around a distant civilization, but rather confirms that the compounds required for life can form in the cold, dark, and mostly empty reaches of outer space.