Rocks from Ryugu asteroid extremely black, have many cavities

The Yomiuri Shimbun

13:26 JST, December 22, 2021

The rocks brought back to Earth from the asteroid Ryugu by the Hayabusa2 space probe are extremely black and have many cavities, according to the Japan Aerospace Exploration Agency (JAXA).

A team of researchers from JAXA and other institutes compiled an initial analysis, and two papers were published on Tuesday in a British scientific journal.

The rocks have been attracting attention as they could hold clues about the early days of the solar system.

The initial analysis revealed that the rocks are dark black, reflecting only 2% of light. The cavity ratio is 46%, making them more porous than meteorites.

The microscopic structure of the rock, which is likely formed when rocks are exposed to high temperatures, was not observed, suggesting that its properties may not have changed significantly since the birth of the solar system. Teams from Japan and abroad are now conducting detailed analysis, and the results will be announced in the spring.

“We hope it will shed light on the mystery of the early state of the solar system and how the solar system evolved,” said Hideaki Miyamoto, a professor in the Department of Earth and Planetary Science at the University of Tokyo.