'Sugar molecules that spurred life on Earth found in space rocks'

Researchers have, for the first time, found the presence of sugar molecules involved in the formation of early life in meteorites, an advance that sheds more light on the potential role played by space rocks in sparking life on the Earth.

The study, published in the journal PNAS, suggests that sugars important for biological processes, such as ribose, can form in space, and the arrival of such sugars on Earth may have sparked the formation of some of the earliest complex biological molecules.

The researchers, including Yoshihiro Furukawa from Tohoku University in Japan, analysed three stony, non-metallic, carbon rich meteorites -- one of them being the Murchison meteorite that landed in Australia in 1969.

They said extraterrestrial samples containing amino acids and other biological building blocks were found in earlier studies, and added that sugars were some of the essential elements of biological systems.

The study revealed that ribose -- a foundational component of ribonucleic acid (RNA) -- was present in the meteorites, as well as other biologically important sugars.

"Ribose is particularly essential as a building block of RNA, which could have both stored information and catalysed reactions in primitive life on Earth," the researchers wrote in the study.

With further analysis, they also found that the sugars were extraterrestrial in origin, and not the result of contamination here on the Earth.

The researchers also conducted a laboratory simulation experiment of a potential sugar formation reaction in space.

The presence of pentoses (sugar molecules containing five carbon atoms) in meteorites, and the composition of the products of the laboratory simulation suggest that the sugars found in the space rocks were formed by a process called formose reaction, the researchers said in the study.

The sugars may have formed before, or immediately after the formation of the asteroids from which the meteorites originated, the study said.

The researchers suggest that early life forming molecules, such as ribose, may have been delivered to an early Earth by space rocks.