Astronomers have made a sweet discovery: simple sugar molecules floating in the gas around a star some 400 light-years away, suggesting the possibility of life on other planets.

The discovery doesn't prove that life has developed elsewhere in the universe—but it implies that there is no reason it could not. It shows that the carbon-rich molecules that are the building blocks of life can be present even before planets have begun forming.

Scientists use the term "sugar" to loosely refer to organic molecules known as carbohydrates, which are made up of carbon, hydrogen, and oxygen.

The molecules that the team detected in space are the simplest form of sugar, called glycoaldehyde, explained lead astronomer Jes Jørgensen of Denmark's Copenhagen University.

Glycoaldehyde can be found on Earth, usually in the form of an odorless white powder. While it isn't used to sweeten foods, it is important because scientists think it plays a key role in the chemical reaction that forms ribonucleic acid (RNA), a crucial biomolecule present in all living cells.

It's still unclear exactly how glycoaldehyde is produced in space, but observations suggest it forms on ice-covered dust grains in the dense, cold parts of interstellar molecular clouds, Jørgensen said.

Sugary Find a First in Space

This marks the first time sugar has been spotted so close to a sunlike star.

Previously, glycoaldehyde had been found in only two other places in space: near the center of the giant cloud of gas and dust at the heart of our own Milky Way galaxy, and in a massive star-forming region located 26,000 light-years from Earth.

"Both of these regions are much further away and were observed with much worse resolution, [so] it was not possible for the astronomers to pinpoint the location of the molecules," Jørgensen said.

The new discovery, which focused on the warm gas swaddling a young star called IRAS 16293-2422, was made using the Atacama Large Millimeter Array (ALMA), a large radio telescope located in Chile.