Scientists believe that Ryugu is the best example of primordial material, and it may help to solve the mystery surrounding how the sun formed.

Samples from the diamond shaped, half-mile diameter space rock were returned to Earth for study by the Japan Aerospace Exploration Agency (JAXA) in 2020.

According to the University of Queensland team, the samples were also one of the most darkly colored materials. They reflect only two percent of light, which was revealed in a new analysis.

These are very porous. They could be the answer to how life began on Earth at 4.5 billion year ago. 

Samples from the diamond shaped, half-mile diameter space rock were returned to Earth for study by the Japan Aerospace Exploration Agency (JAXA) in 2020

The Japan Aerospace Exploration Agency (JAXA), in 2020, received samples of the half-mile long space rock with a diamond shape.

New analysis of those samples revealed they are also among the darkest materials ever examined, reflecting just two per cent of the light that hits them, according to the team behind one of two studies, from the University of Queensland, Australia

A new analysis of those materials revealed that they also reflect just 2 percent of the light hitting them. This is according to researchers from University of Queensland (Australia). 


A second study of samples taken from Ryugu analyzed their origin and makeup.

One discovered that the material was extremely opaque, reflecting only 2 percent of the light it receives.

The study revealed that the sample was extremely porous. This confirms previous studies.

It was found to be made from a clay-like matrix with carbon-linked material. 

Ryugu is a near-Earth carbon-type asteroid. It measures approximately 3,000ft in size and orbits between Mars and Earth. It crosses Earth’s orbit occasionally.

The journal Nature Astronomy published two papers by researchers that examine rock samples brought back from the Earth in Japan.

Around 0.19 ounces worth of rock reached Earth on December 2020. It was returned from Ryugu by the Hayabusa2 spacecraft.

Toru Yada, a colleague from the University of Queensland and others, examined how light samples reflect, finding that it was one of the most dark objects ever seen.

It was only 21% of what light hit it, and so called pitch-dark.

The bulk density of the samples also was lower than they expected in a carbonaceous meteorite, which is what this closely resembles.

The rocks’ porous nature suggests they are porous and have pockets of open space that allow water and gas to flow between the grain of the material.

Cedric Piilorget (and his team) from Paris-Saclay University, France examined the chemical composition of the material by studying it under different wavelengths, in both the visible-infrared and ultraviolet spectrums.

Professor Pilorget and colleagues discovered that the sample is composed of a hydrated matrix, such as clay, with a variety of organic matter embedded.

But, the researchers also noticed that parts of the sample included substances like carbonates or volatile compounds.

Pilorget explained that while certain material characteristics were very similar to the carbonaceous-chondrites we had in our collection, others were quite distinct. 

Professor Pilorget and colleagues discovered that the sample is composed of a hydrated matrix, such as clay, with a variety of organic matter embedded

Professor Pilorget discovered with his colleagues that the sample was composed of a matrix of clay and a range of organic matter.

Hayabusa2 first visited Ryugu in June 2018; from there, it took measurements and samples of the asteroid, before leaving for Earth in November 2019

Hayabusa2 visited Ryugu for the first time in June 2018. From there it collected samples and took measurements of the asteroid before departing for Earth in November 2019.

This isn’t the first study to suggest that Ryugu may be more porous than first thought, with a team from Rikkyo University determining that boulders on the asteroid would have an average porosity of more than 70 per cent.

It would also be the highest level of any proto-planets or planetesimals that existed at the dawning of the solar system (4.6 billion years ago). 

The samples open up new questions about the origins of the solar system. However, they confirm Ryugu’s status as a carbon-rich, chondrite-asteroid. They are darker and porous than meteorite samples.    

Pilorget said that while we’re only just beginning our investigation, the results of the tests suggest that these materials are some of the most primitive material in the laboratory, and he spoke to LiveScience in an interview.

Although they don’t have an exact date, the scientists believe that the materials are from the very early formation of the solar systems. They hope to be able to verify this age through future research.

The material was kept in a vacuum room to help them understand its origins. 

Toru Yada, a researcher at LiveScience said that this means they can handle the samples “without exposing them for Earth’s atmosphere”.

NASA’s spacecraft, carrying samples from the space rock Bennu, is returning to Earth. Multiple agencies have also been working towards a Mars sample return mission.

Nature Astronomy published the findings. 


Jaxa’s Hayabusa Two probe visited the ancient asteroid Ryugu in a bid to help scientists better understand the origins of the solar system.

It was launched on December 14, 2014, and reached the space rock in dice shape on June 27, 2018. Samples were returned to Earth by the probe in December 2020. 

It was equipped with four surface landers and an assortment of cameras. The probe also had an explosive device to dig out subsurface rock samples.

Ryugu is a Type C Asteroid. There are traces of organic material and water in Ryugu.