After a six-year voyage, a daring spacecraft named Hayabusa2 returned to Earth’s atmosphere in late 2020 and sank off the outskirts of Australia. When JAXA was opened by Japanese space agency investigators, they found its valuable cargo sealed and intact: Hayabusa2 managed to pull a handful of dirt out of the surface of a fast-moving asteroid.
Scientists have now begun to predict the first results of the analysis of this extraordinary sample. Those who have found it suggest that this asteroid is a piece of the same thing that came together in our sun four and a half billion years ago.
“Earlier we had only a few of these rocks to study, and they all fell to Earth and were meteorites that had been stored in museums for decades or centuries, and these changed the composition,” said geochemist Nicolas Dauphas, one of the three Universities. Chicago researchers who have worked with a team of international scientists led by Japan to study fragments. “Having samples from outer space is simply unbelievable. They are witnesses to parts of the solar system that we would not otherwise explore.”
In 2018, Hayabusa2 landed on a floating asteroid called Ryugu and collected particles from its surface and below. After spending a year and a half orbiting the asteroid, it returned to Earth with a closed capsule containing five grams of dust and rocks. Scientists around the world are eagerly awaiting a single sample that can help us redefine our understanding of how the planets evolve and how our solar system was created.
Scientists are particularly excited that these particles would never have reached Earth without the protective barrier of a spaceship.
“Usually, all we get from studying asteroids is enough pieces to reach the earth as meteorites,” said Andrew M. Davis, a geochemist at UChicago, another member of the analysis team. “If you took this handful and threw it into the atmosphere, it would burn. You would lose it, and a lot of evidence about the history of this asteroid would go away.
“Actually, we haven’t had a sample like this before. It’s impressive.”
Davis, Dauphas, and UChicago colleague Reika Yokochi are part of a group that has come together to help Japanese researchers analyze the samples. Every part of the contents of the capsule is being scrutinized. Yokochi is part of a group that is studying the gases trapped in the capsule or dirt. The chemical and isotopic compositions of Dauphas and Davis are part of a group studying the grains to reveal their history.
The first collection of these results was published in Science on June 9, she unveiled Ryugu’s makeup.
The rock is similar to a class of meteorites known as “Ivuna-type carbonaceous chondrites”. These rocks have a chemical composition similar to that we measure from the sun, and are believed to have been around four and a half billion years since the beginning of the solar system – before the sun came up, the moon. and Earth. [should Moon be capitalized to distinguish it from other moons?]
Back then, everything that existed was a huge, rotating cloud of gas. Scientists believe that most of this gas was carried to the center and created a star we know as the sun. As the traces of this gas spread and cooled in a disk, they became rocks, which still float around the solar system today; it seems that Ryugu may be one of them.
Scientists say the fragments show signs of being soaked in water at some point. “A set of ice and dust must be depicted floating in space, turned into a giant ball of mud, from the melting of ice by nuclear energy, from the disintegration of radioactive elements that formed when the asteroid formed,” Dauphas said. But surprisingly, today the stone itself looks pretty dry.
Using radioisotope dating, Ryugu estimated that the water circulation created the solar system and changed it in about five million years.
These findings are of particular interest to researchers because they suggest similar formation conditions between comets and asteroids such as Ryugu.
“By examining these samples, we can limit the temperatures and conditions they must be in during their lifetime, and try to understand what happened,” Yokochik explained.
He compared the process to figuring out how to make a soup, but only to the final result rather than the recipe: “We can take the soup and separate the ingredients, and try to tell how much it was heated and how much it was heated. In what order.”
Scientists have indicated that one percent of the discovery will be discarded so that it can be studied with more advanced technology in the future, as we did with Apollo’s lunar samples.
“When we got Apollo’s lunar samples 50 years ago, our ideas about how the moon formed completely changed,” Davis said. “We are still learning new things from them as our tools and technologies have advanced.
“The same thing will happen with these samples. It’s a gift that continues to be gifted.”
This mission is the first of several international missions to bring samples from another asteroid called Bennu, as well as unexplored areas of our lunar, Mars, and Mars phobos. All of this should happen in the next 10 to 20 years.
“It’s been very much under the radar for the public and for some decision makers, but we’re entering a new era of exploration of an unprecedented planet in history,” Dauphase said. “Our children and grandchildren will see asteroids, Mars and, hopefully, other planets when they visit museums.”