Assessing the Most Pre-Historic Bits
The tiny rock particles collected from the asteroid Ryugu are some of the most primitive bits of material ever analysed on Earth, and they may provide insight into the solar system’s origins.
162173 is an asteroid. According to sources, Ryugu has a diameter of 2,953 feet (900 metres) and orbits the sun between Earth and Mars, occasionally touching Earth’s orbit. As it hurtles through space, the carbonaceous, or C-type, asteroid spins like a top, and like other C-type asteroids, Ryugu is expected to include material from the nebula (giant cloud of dust and gas). Scientists believe they gave birth to the sun and its planets billions of years ago.
In 2019, the Japanese spacecraft Hayabusa2 gathered samples from the surface of Ryugu, and on Dec. 6, 2020, the Japanese spacecraft Hayabusa2 collected samples from the surface of Ryugu. In a sealed container hidden into the reentry capsule, those samples were successfully brought to Earth. Scientists share data from the initial investigation of these amazing chunks of space rock in two new studies published Monday (Dec. 20) in the journal Nature Astronomy.
“We are only at the beginning of our investigations,” Cédric Pilorget said, “but our findings suggest that these samples are among the most primal material available in our laboratories.” He is an assistant professor at the Paris-Saclay University’s Institute of Space Astrophysics and the first author of one of the papers. The material’s actual age is unknown, but future research should reveal it.
About the Asteroid Samples
The asteroid samples include around 0.2 ounces (5.4 grammes) of material in total. The largest rock particles are around 0.31 inches in diameter (8 millimetres), while the smallest is below 0.04 inches (1 mm), and similar to fine dust. The samples appear to be extremely dark bits of black pepper to the human eye, according to Toru Yada, an associate senior researcher at the Japan Aerospace Exploration Agency and the study’s first author.
The scientists discovered that the pitch-dark asteroid pieces only reflect roughly 2% to 3% of the light that touches them. The researchers were also shocked to find that the samples had a reduced bulk density, which is defined as the mass of the particles divided by the entire volume they inhabit. When compared to carbonaceous meteorites, this was a significant difference. This discovery suggests that the rocks are highly porous, implying that there are many pockets of empty space between the individual grains of components in the rocks, allowing water and gas to seep through.
According to sources, this discovery corresponds to preliminary data collected by the Hayabusa2 mission, which also suggested that the rocks on Ryugu’s surface are particularly porous.
“We have to understand why and what it means for the genesis and evolution of this material,” he said of the Ryugu samples, which are among the darkest ever analysed. In addition, evidence of ammonia-rich chemicals was identified in the rock. This could have ramifications for Ryugu’s genesis and our understanding of primordial matter.