This will allow scientists to better understand the process of formation of our planetary system.
scientists, showed that they are probably the “purest” sample of space rock that scientists have ever encountered. Moreover, the composition of this soil indicates that it is part of the outer solar system, reports Science Alert.
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This not only gives scientists a unique tool for understanding the formation and development of our planetary system, but also provides a context in which to interpret other cosmic species , which were contaminated by contact with the Earth.
The Sun and the system around it formed about 4.6 billion years ago. That's a very long time and a lot has changed since then. However, there are “time capsules” that help us understand what the structure of the early solar system was like. These are “space rocks”, such as asteroids and comets.
Getting such a “space rock” is not an easy task, and obtaining its samples is even more difficult. Usually, scientists rely on rocks that fall to Earth. The meteorites, known as carbonaceous chondrites, were the best available tool for studying the composition of asteroids that could have delivered water to Earth when the solar system was still forming.
But the results are distorted by some version of the “survivor's paradox.” Only the strongest rocks that can survive entering the atmosphere can reach the surface of our planet. But even then, their substance is polluted by the environment.
But in 2020, the Hayabusa-2 station delivered samples of the Ryugu asteroid to Earth, and scientists have been studying them ever since. In the course of a new study, scientists found out that the asteroid has an important difference from carbonaceous chondrites. Ferrihydrite (compounds of iron and oxygen) and sulfate (sulfur and oxygen) are absent from asteroid samples. Because these compounds were found in meteorites, they were thought to be a component of extraterrestrial materials. The absence of them in Ryugu suggests that they were the result of terrestrial weathering of meteorites.
This means that during further studies of meteorites, scientists should consider this possibility. Other asteroid samples collected in space may shed more light on this question.
“In this study, we demonstrate that [carbonaceous] meteorites, despite their geochemical importance as indirect indicators of the overall composition of the Solar System, are samples contaminated by the Earth's environment,” the researchers wrote in their paper.
Recall, on the morning of November 13, 2019, “Hayabusa-2” turned on its engines as part of the departure from Ryugu orbit and return to Earth maneuver. At that moment, it was at a distance of 20.11 kilometers from the surface of the asteroid. After 15 minutes, the mission team received a signal that the maneuver was successful.
On December 6, 2020, the station dropped a capsule containing soil samples from asteroid Ryugu to Earth. On December 15, specialists opened the A section of the capsule and found soil inside it, which is believed to have been collected during the first approach from Ryugu in February 2019.
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Since the station left a supply of fuel for the engines, and scientific equipment is working, scientists decided to continue her research program. The main target of the station was the 30-meter near-Earth asteroid 1998 KY26. In July 2026, the station will pass by an additional asteroid – the 700-meter asteroid 2001 CS21.
