Samples of the Ryugu asteroid turned out to be the cleanest in the Solar System

Scientists continue to study samples of the Ryugu asteroid, which are the “cleanest” parts since the formation of the Solar System. Recently, “molecules of life” have been discovered in them. Now scientists have made a new discovery.

The 31 milligrams of dust and debris from the Ryugu asteroid in this photo are the cleanest particles of the Solar System that have ever been studied by scientists. Photo: Science

A new analysis of the Ryugu material confirms that the porous asteroid is rich in carbon and is “extremely primitive” in its composition. It is also a representative of a rare class of asteroids known as the CI-type, researchers report online in the journal Science.

Japanese scientists have at their disposal only 5.4 grams of dust and small stones from different places on the surface of Ryugu. They were obtained with the help of the Hayabusa-2 mission apparatus, which delivered them to Earth in December 2020. Using 95 milligrams of asteroid debris, the researchers measured dozens of chemical elements in the sample, and then compared the content of some of these elements with the content measured in rare meteorites classified as type CI chondrites. The comparison confirmed that Ryugu is a type CI chondrite. Only less than 10 meteorites found on Earth belong to CI chondrites.

Ryugu asteroid. Photo: JAXA

The study also showed that, unlike Ryugu, meteorites appear to have been changed or polluted by the Earth’s atmosphere or even human exposure over time. 

“The Ryugu sample is much cleaner and more primitive,” says Hisayoshi Yurimoto, a geochemist at Hokkaido University in Sapporo, Japan.

The researchers also measured the content of manganese-53 and chromium-53 in the asteroid and determined that the melted water ice reacted with most minerals about 5 million years after the formation of the Solar System, changing their composition, Yurimoto says. This water has since evaporated, but the “distorted” minerals are still present in the samples. Scientists continue to investigate the composition of the asteroid to learn more about the Solar System.

It was previously assumed that the Ryugu asteroid could be a “burnt out” comet.

Follow us on Twitter to get the most interesting space news in time