Soil samples from the Ryugu space rock are remarkably old and dark

Last year, the Japanese space probe Hayabusa2 returned soil samples from the asteroid Ryugu. The first analyzes of the rocks show that the space rocks have a primitive composition, as well as a special dark color.

The asteroid Ryugu contains some of the darkest and oldest known material in the solar system. This is evident from the first analyzes of soil samples from space rocks.

It’s only the second time an asteroid has been sampled. Japanese space probe Hayabusa2 Soil Sampling in 2019 in a The package landed on Earth last year.

Origin

The collected material weighs about 5.4 grams and comes from the surface of the asteroid. Many of the minerals and materials in the soil sample are consistent with those found in meteorites found on Earth. In addition, they also contain a whole host of unusual substances, such as water molecules and organic matter, that contain carbon atoms.

“Although most matter is only present in very small amounts in matter – a maximum of a few percent – it probably tells us a lot about the origin of the solar system and about the asteroid Ryugu itself,” he says. Cedric Bellorgette, a planetary scientist at the University of Paris-Saclay in France. He is part of the international team of researchers that examined soil samples.

microscope

For the second analysis of soil samples, a research team from the Japan Aerospace Research Agency used multiple imaging techniques that leave the sample intact. For example, they used a spectrophotometer and a special microscope to study the composition of minerals in the grains.

These analyzes confirmed several observations made by the Hayabusa2 space probe sensors early in 2019 when soil samples were collected. In addition, the grains turned out to be particularly dark, in terms of the light they reflected. It turned out to be darker than the substance of terrestrial meteorites.

That could mean two things: either the Ryugu granules are made up of a unique mixture of chemicals, or Earth’s atmosphere somehow lights up meteors when they collide here. “To make a substance lighter, it has to reflect differently,” says the astrobiologist. Engy almonds ten kit from Utrecht University, not associated with this study. This color difference could mean that due to heat from friction with the atmosphere during entry, something has changed physically or chemically in the material. But they clearly don’t have enough data to say how dark Ryugu is.

chain collision

The second analysis also showed that Ryugu is very porous. This may be the result of asteroid formation, which formed from a series of collisions and collapses of ancient asteroids.

“When our solar system came into being, there was a lot of dust and pebble-like material smashing together,” says Tin Kate. Sometimes they would stick together resulting in larger and larger stones and boulders. Planets eventually formed from these collisions. But there was material left and the engagement was not over. The remaining asteroid reservoirs also continued to collide, thus shattering and forming new asteroids again.

molecules and minerals

The fact that Ryugu grains contain water and carbon indicates that Ryugu originated from the fringes of the early solar system. The presence of nitrogen-based substances may determine the origin of Ryugu.

At the same time, the absence of some substances, including calcium and aluminum-based minerals, indicates that the asteroid did not form in the early years and the hottest regions of the solar system. This is what the geologist says Ashley King from the Department of Minerals and Planetary Science at the Natural History Museum in London, who was not involved in this research.

King said that these preliminary analyzes cannot yet accurately determine Ryugu’s age. However, the presence of carbon-containing and dark, well-preserved material suggests that Ryugu may have formed shortly after the formation of the Solar System, approximately 4.6 billion years ago. “This is the purest material we can get and it takes us back to the starting point of the solar system,” King said.

Ten Kate is also pleased with this new research data: “If this substance is more or less than it was now 4.6 billion ago, that offers all kinds of possibilities for those organic molecules. To land on the surfaces of the planet About the time when life arose.