TOKYO: Pebbles and sand brought by the Hayabusa2 explorer from Ryugu are “a representative sample” of the asteroid, a Japanese team has said.

The team, including researchers from the Japan Aerospace Exploration Agency, or JAXA, and the University of Tokyo, published this on the Thursday edition of US journal Science.

Hayabusa2 landed on Ryugu twice, in February 2019 and July the same year, and collected samples of the asteroid. A total of 5.4 grams of pebbles and sand were in a capsule brought back to Earth in December 2020.

The team conducted a detailed analysis of images of materials of Ryugu captured at the time of Hayabusa2 ‘s landings on the asteroid and identified the shapes of 67 items including pebbles.

It also compared the characteristics of the collected samples with those of pebbles and sand shown in a number of images taken at many locations on Ryugu by the Minerva-II rover sent from Hayabusa2 to the asteroid in September 2018.

The team found that the pebbles sampled from the landing sites show “morphological variations ranging from rugged to smooth” and have a variety of shapes such as “quasi-spherical” and “flattened.”

Their diverse colors, shapes and structures are “consistent” with the observed materials in the images, it said.

“We could bring back materials similar to those in the images,” University of Tokyo professor Shogo Tachibana, a member of the team, said.

He said: “We can’t understand the whole picture of Ryugu if the locations where the samples were taken had been special. But we will be able to figure it out now that the collected items are representative samples of the asteroid.”

JIJI Press