Organic molecules have been found in samples collected by the Japanese spacecraft Hayabusa 2 from the nearby asteroid Ryugu.

When the researchers analyzed samples collected from two different locations on the asteroid, they found uracil, one of the building blocks of RNA, as well as vitamin B3 (niacin), which is a key factor in metabolism in living organisms.

Uracil is one of the nitrogenous bases of DNA and RNA nucleotides, proteins and molecules that contain genetic information and instructions for the cells of living organisms. A study detailing the results was published Tuesday in the journal Nature Communications.

Ryugu is a diamond-shaped, carbon-rich asteroid. Its width is about a kilometer. THayabusa2 was the first mission to send an asteroid sample back to Earth..

Shooting asteroids

A Japan Aerospace Exploration Agency mission took a sample from the asteroid’s surface in February 2019 and then fired a copper “bullet” into the asteroid, creating a 10-meter-wide crater. A sample from the crater was collected in July 2019 and then Hayabusa 2 returned, delivering the sample to Australia in December 2020.

In previous analyzes, the researchers identified amino acids and other molecules in Ryugu samples, while uracil and niacin have also been found in meteorites that have fallen to Earth..

“Scientists have found nitrogenous bases and vitamins in carbon-rich meteorites, but there has always been the question of contamination from terrestrial exposure,” said lead author Yasuhiro Ohba, an assistant professor at Hokkaido University in Japan. “Because the Hayabusa 2 spacecraft collected two samples directly from the asteroid Ryugu and brought them back to Earth in sealed capsules, the contamination scenario can be ruled out.”

Building blocks of life in space

The researchers discovered the molecules when they immersed the particles collected by Ryugu in hot water and analyzed the results using a variety of observation methods such as water chromatography and spectrometry. The team found characteristic traces of uracil, niacin, and other nitrogen-containing organic compounds.

“Other biological molecules were found in the sample, such as a range of amino acids, amines, and carboxylic acids, which are found in proteins and metabolism, respectively,” says Oba.

“Main stones” on meteorites

Findings based on Ryugu specimens support the indication that The building blocks of life came from outer space and were brought to Earth billions of years ago on meteorites.. Molecules likely formed from photochemical reactions in ice in space before our solar system even formed.

The concentrations of molecules in the two samples were different, but this is likely due to exposure to the harsh conditions of space. It is possible that Ryugu was once part of a larger celestial body such as a comet before it was shattered into pieces by collisions with other celestial bodies. It’s also possible that when space rocks crashed into other planets in our solar system, they were carrying some of the building blocks of life.

“I can’t say that the presence of such substances directly means the appearance or presence of extraterrestrial life, but at least their components, such as amino acids and nucleobases, can be found everywhere in the Cosmos,” commented Ohba.

Now the researchers want to know how widespread these molecules are in asteroids. A sample of another asteroid, Bennu, will be brought to Earth in September by NASA’s OSIRIS-REx spacecraft.

“The discovery of uracil in Ryugu samples supports current theories about the source of nitrogenous bases on the early Earth,” Ohba said. “NASA’s OSIRIS-REx mission will return samples from the asteroid Bennu this year, and a comparative study of the composition of these asteroids will provide additional data to develop these theories.”

Source: CNN