Scientists discover building blocks of RNA in asteroid sample

March 21 (UPI) -- Scientists have discovered some of the building blocks of life in samples recovered from the Ryugu asteroid. The discovery lends credence to the idea that many of the important chemicals that formed life on Earth came from outer space, researchers say.

The sample was collected by the Japanese Space Agency's Hayabusa2 spacecraft in 2018 and returned to Earth in 2020.

The samples are the oldest scientists have been able to study in a lab, as they predate the full formation of Earth and offer clues into the kinds of chemicals that were being seeded onto the planet in its primordial phase.

An initial examination of the sample revealed that it contained organic matter, including racemic amino acids, one of the building blocks of ribonucleic acid or RNA. The initial analysis also revealed the presence of other organic compounds including, alkylamines, polycyclic aromatic hydrocarbons, nitrogen heterocyclic, and carboxylic acids.

Further research, lead by Yasuhiro Oba of Japan's Hokkaido University, and published in the scientific journal Nature, uncovered uracil and nicotinic acid. The discovery of uracil is significant because it is key nucleases in RNA.

"The present study suggests that such molecules of pre-biotic interest commonly formed in carbonaceous asteroids including Ryugu and were delivered to the early Earth," researchers said in the study.

A difference in uracil concentration levels between samples is likely due to exposure to cosmic rays, the researchers said.