2023-06-14 12:42:32
A research team from the University of Lausanne and the Natural History Museum in Geneva will be able to work on dust from the asteroid Ryugu, one of the most primitive objects in the solar system. This will involve analyzing the chemical composition of these samples.
Scientists from the Lake Geneva region have received a mandate from the Japanese Aerospace Exploration Agency (JAXA) to carry out this analysis work. Studying these little bits of asteroid dust is a step back in time. Thanks to it, researchers hope to deepen their understanding of the water and sulfur cycle in the early Solar System.
The Japanese probe Hayabusa 2 landed on the asteroid Ryugu on July 11, 2019 and collected 5.4 grams of material. Scientists hoped to bring back about 100 grams. [ISAS-JAXA – AFP]
Ryugu is indeed the witness of the time when the Solar System and the planets were formed. The samples taken from the surface of the asteroid are in a unique state of preservation and are a wealth of information for research. They may help to answer the question of the origin of water on Earth and therefore, perhaps, of life!
This dust which will be studied in Lausanne and Geneva, received in a postal parcel, comes from the 5.4 grams of the asteroid Ryugu which was brought back, in 2020, by the Japanese space probe Hayabusa 2. The celestial object of 900 meters in diameter, which fascinates scientists so much, is located 300 million kilometers from Earth and is approximately 4.6 billion years old.
Meteorites of the same type as Ryugu that can be found on Earth have passed through the atmosphere: “They are heated extremely strongly and potentially contaminated. If they remain on a glacier or in a desert for a long time, they can also undergo an alteration “, explains Professor Johanna Marin Carbonne from the Faculty of Geosciences and the Environment at UNIL.
Even getting dust from this asteroid is fantastic: “There, we have material that has never been in contact with an atmosphere. It was taken and then sealed and only opened in laboratories”, she notes to the microphone from CQFD.
>> Listen to the interview of Prof. Johanna Marin Carbonne, researcher at the Faculty of Geosciences and Environment of UNIL, in CQFD:
“Bricks necessary for life”
Many studies are already underway around the world on these dust particles from space. This is to obtain information on the formation of the Solar System and the planets and even on the origin of life. One of the searches thus revealed the presence on Ryugu of “the basic bricks necessary for life”. “This asteroid is unique because it has the composition of a class of meteorites called carbonaceous chondrites which have the composition closest to the Sun”, specifies the researcher in a UNIL video.
The two samples, included in an epoxy resin, which were entrusted to UNIL and the Museum of Natural History in Geneva are tiny. Their size is about 50 to 200 micrometers, or about ten times the diameter of a human hair, which measures about 80 microns. This asteroid dust will be analyzed with the ion probe SwissSIMS, in the premises of UNIL. Tiny holes are made with this mass spectrogram; the samples will therefore be returned almost unaltered.
water and sulfur
The evolution of sulfur and the nature of the water are the main points of the studies which will be carried out in French-speaking Switzerland by specialists in geoscience. The idea is to try to reconstruct the composition of the oldest water in Ryugu and see if this water is comparable to that found on Earth. Water could indeed have been brought to Earth by asteroids.
“The asteroid is an aggregate of dust which is made up of lots of minerals, some of which contain sulphur: they are called sulphides. We can precisely measure their composition and know exactly how they were formed”, describes Johanna Marin Carbonne. “The big question for us is whether we have sulphides that formed when the asteroid Ryugu aggregated, at the very beginning of the formation of the Solar System.” The analysis of the composition of sulfur will also make it possible to understand the formation of atmospheres.
We will measure the water and see if it has the composition of the Sun or pre-solar gas.
![The teacher. Johanna Marin Carbonne from the Faculty of Geosciences and Environment of UNIL. [Alain Herzog - UNIL]](https://www.rts.ch/2023/06/14/12/35/14102141.image?w=320&h=320)
Under the right conditions, ice and dust clump together as a system begins to form around a star: “We have a gas of dust and water that is very hot, with differences in temperature”. In some environments, the two somehow stick together.
“Ryugu formed quite far from the Sun, but after it approached the Sun and, therefore, the ice melted, it made water. We want to look at the effect of this water on the minerals”. To measure the amount of water on the total scale of the sample, the scientists looked at the hydrogen composition, since water consists of two hydrogen atoms and one oxygen atom (H2O).
Phosphates are also analyzed, because they are formed very early in the asteroid and can contain hydrogen and other volatile elements: “We will measure this water – in reality its constituent elements – and see if it has the composition Sun or pre-solar gas”. It is the whole history of water that will be able to be evoked.
>> Watch the UNIL video on samples from the asteroid Ryugu:
In Switzerland, the joint project of theUNIL and the Natural History Museum of Geneva is not the only one to have received samples of Ryugu. ETHZ is also working on the asteroid. It should also be noted that half of the 5.4 grams that reached Earth was kept for future generations.
Stéphanie Jaquet and the ats
1686751599
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