Ancient asteroid samples could reveal crucial clues

Rubble retrieved from asteroid Ryugu are among the most uncontaminated Solar System materials ever studied.

Asteroid Ryugu particles are the most uncontaminated Solar System materials. (NASA)

Ancient particles from an asteroid in near-Earth solar orbit could contain crucial clues about the outer solar system. The samples of rocks and dust received from the Ryugu asteroid are the most uncontaminated Solar System materials. According to a new study published in Nature Astronomy, the composition of particles suggests that they contain chemistry from the outer reaches of the system that could give us some crucial information. "Ryugu particles are the most uncontaminated and unfractionated extraterrestrial materials studied so far, and provide the best available match to the bulk Solar System composition," said a team led by cosmochemist Motoo Ito of the Japan Agency for Marine-Earth Science Technology (JAMSTEC).

As shared by Sciencealert.com, the asteroid samples were brought by Japanese craft Hayabusa2, a mission conducted in 2019 by Japanese state space agency JAXA. The spacecraft returned to Earth in 2020 with 5 grams of particles from the space rocks. Since then, researchers have been avidly studying the particles. The findings suggest that the composition of these particles is very similar to those carbonaceous chondrites, and hence scientists classified it as a C-type asteroid. “It also contains prebiotic molecules and may have once been a comet,” reports the portal.

The new in-depth analysis says that the Ryugu started its life much before the Sun as abundances of heavy hydrogen and nitrogen in the asteroid are consistent with an origin in the outer Solar System. Hence, these particles will allow scientists to study the chemistry of the early Solar System and how it all came together.

"In this study we demonstrate that [carbonaceous] meteorites, despite their geochemical importance as proxies of the bulk Solar System composition, are terrestrially contaminated samples," the researchers wrote. They also mentioned that the findings of this study demonstrate the importance of direct sampling of primitive asteroids and their return in uncontaminated conditions.