Asteroid Ryugu contains material older than the planets

Ryugu contains some of the most primitive material ever studied on Earth, dating back to just 5 million years after the formation of the Solar System according to analyses of samples retrieved by Japan's Hayabusa2 mission. Because it's so old, it's made of the same material that formed the planets. "Ryugu is one of the building blocks of Earth," Hisayoshi Yurimoto, a professor at Hokkaido University in Japan, said.

- Mike Wall

The Japan Aerospace Exploration Agency's Hayabusa2 launched in 2014 and arrived at Ryugu in 2019. It retrieved two small samples of regolith from the asteroid. These samples then landed on Earth in a capsule equipped with a parachute in December 2020. Upon their return, the samples were distributed among scientific groups, including one team led by Tetsuya Yokoyama, a professor at the Tokyo Institute of Technology. The team's newly published results suggest that the composition of the samples is the closest match to the solar nebula - the gas cloud that condensed to form the Sun and planets - ever found, made up of the ingredients that formed the Solar System 4.5 billion years ago. The findings support previous research that also concluded that Ryugu was made of primitive material, but until now it