It is the result of a journey that began more than seven years ago. On December 3, 2014, the Hayabusa2 probe left our planet in the direction of the asteroid Ryugu. The encounter took place in June 2018. She first observed it for a few months, then dived on it twice to collect samples, before bringing them back to Earth in December 2020.
It is today that the results begin to fall. A study published in February 2022 in the journal Science reveals that the appearance of the pebbles and grains of sand collected is similar to what had been observed on the asteroid, says Patrick Michel, CNRS research director at the Lagrange laboratory of the Côte d’Azur Observatory (Nice) and involved in the mission: “ The samples are representative of what is on site. We did not take a specific rock from a particular location that would only tell us regarding a small part of the object. »
Very black, rough for some, but sometimes smooth, spherical or flat… The pieces collected are varied and have already been the subject of two publications in December 2021. One concerned the porosity of the samples. ” It gives information on how the asteroid was formed “says Patrick Michel. The other concerned the presence of organic matter and water. Verdict: hydrated and carbonaceous materials are present. ” This will allow us to move forward on the role of asteroids in the emergence of life on Earth “, he continues. Many other studies will follow.
Extended trip
The collection of samples on Ryugu having been better than expected, the Nice researchers hope to recover some to carry out mineralogical analyzes by cathodoluminescence in the team of Guy Libourel, cosmochemist and professor at the University Côte d’Azur. ” It’s a technique that we are the only ones to have here in Nice “says Patrick Michel. It is already planned to do so on a sample of Bennu, an asteroid explored by the Osiris-Rex mission of the American Space Agency, part of the harvest of which – which should arrive on Earth in 2023 – will go to the Côte d’Azur Observatory. ” It would be interesting to compare the results “, adds Patrick Michel.
As for the ship that delivered the Ryugu samples to Earth in December 2020, it continues on its way. As it is still functioning and still has fuel, the Japanese Space Agency has decided to extend its mission. It is heading towards 1998 KY26, an asteroid 30 meters in diameter which rotates on itself in 10 minutes. ” Some really exciting results might come out of it.warns Patrick Michel. Each new image of an asteroid offered us great surprises. The meeting is scheduled for 2031.