Asteroid Ryugu might contain a building block of RNA

Just 5.4 grams of asteroid soil returned to Earth in 2020 is still providing scientists with a wealth of knowledge.

A new study, published in Nature Communication, has suggested that the asteroid Ryugu contains a building block of RNA called uracil, as well as Vitamin B3.

“Scientists have previously found nucleobases and vitamins in certain carbon-rich meteorites, but there was always the question of contamination by exposure to the Earth’s environment,” Hokkaido University Associate Professor Yasuhiro Oba says.

“Since the Hayabusa2 spacecraft collected two samples directly from asteroid Ryugu and delivered them to Earth in sealed capsules, contamination can be ruled out.”

In the last few years researchers have been finding out whatever they can about the precious space dust. We knew that Ryugu is close to the rare ‘Ivuna-like’ carbonaceous chondrites, that it had formed about 4.5 billion years ago, and barely changed since.

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Scientists have discovered organic compounds like amino acids, alkylamines and hydrocarbons – all of which are the sort of molecules expected to be found in the prebiotic stages of life on Earth.

But this new analysis peered even deeper into the pile of rock, using a small-scale detection technique to be able to find both uracil and nicotinic acid – better known as vitamin B3.

“We found uracil in the samples in small amounts, in the range of 6–32 parts per billion (ppb), while vitamin B3 was more abundant, in the range of 49–99 ppb,” Oba said.

“Other biological molecules were found in the sample as well, including a selection of amino acids, amines and carboxylic acids, which are found in proteins and metabolism, respectively.”

This sort of experiment is incredibly important, as most of our understanding of our Solar System asteroids comes from meteorites which have gone through the harsh heat of an Earth landing. Getting asteroid samples directly from the asteroids allows researchers to be able to analyse the pristine, unchanged space dirt.

Although the researchers still have plenty of asteroid dust to play with, NASA’s OSIRIS-REx mission is returning samples from asteroid Bennu later this year.

Although 5.4 grams is a huge amount in scientific terms, NASA researchers are confident that the spacecraft is returning to Earth with between 400 grams and 1 kilogram of asteroid dust. If this is the case, that much rock will likely to be another bonanza of scientific activity.