Des grains de poussière plus vieux que le Soleil découverts sur l’astéroide Ryugu

Vue d'artiste de la sonde Hayabusa-2 lors de sa deuxième tentative de prise d'échantillons en juillet 2019, près d'un cratère artificiel formé sur l'astéroïde Ryugu en avril. © Akihiro Ikeshit, Jaxa

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[EN VIDÉO] These are all known asteroids in our Solar System.
Look how many there are: here are all the asteroids identified by astronomers since the first discovery in 1801. The number of discoveries has literally increased since the end of the 20th century.

In 1950, Erwin Schrödinger
Erwin Schrödinger was a gifted child of Austrian origin on his father’s side and English on his mother’s side. Coming from a wealthy family, he was educated by tutors … “data-image =” jpg” data-url=”” data-more=”Read more”>Erwin Schrödingerone of the founders of Quantum mechanicshaving worked both for the elucidation of the nature of life and for the appearance of organic matter, nitrogenous matter, etc.
There are different families like:

organic matter, which constitutes living beings (animals or plants) or…” data-image=” jpg” data-url=”” data-more=”Read more”>matter in a pattern of cosmology relativist, he explained in one of four public lectures entitled ” Science as a constituent element of Humanism ” that ” isolated knowledge obtained by a group of specialists in a limited field has no value in itself; It only has value in the synthesis that unites it to all other knowledge and only to the extent that it really contributes, in this synthesis, to answering the question: Who are we? “.

Indeed, we are searching for our roots and our cosmic identity with space missions like that of the Japanese probe Hayabusa-2who was in orbit around the asteroid (162173) Ryugu from June 2018 to November 2019. He collected samples there which have since been arrived on Earth and are still being analyzed.

A presentation of the Hayabusa 2 mission. For a fairly accurate French translation, click on the white rectangle at the bottom right. Then the English subtitles should appear. Then click on the nut to the right of the rectangle, then on “Subtitles” and finally on “Auto translate”. Choose “French”. ©DLR

Therefore, they come from a member of the Apollo asteroid family, asteroids NEO, and is even among those that are potentially dangerous. It had been discovered in 1999 and it quickly became clear that it was part of the C-type asteroids, that is, similar to meteorites. chondrites known carbon on Earth.

Therefore, its chemical composition is close to that of cloud-forming matter.
The quantity…” data-image=”” data -url=”” data-more=”Read more”>cloud molecular and dusty where the Solar system primitive, without the light and volatile elements like ice cream. Therefore, it was a target of choice to understand the origin of the planets and The Sun is the closest star to Earth, from which it is approximately 150 million kilometers away. The Sun is 8.5 kparsecs from the center of the Milky Way. In stellar classification, the sun is a G2-type star.
The mass…” data-image=”” data-url=”https://news.” data-more=”Read more”>Sun and therefore the origin of the biosphere and the noosphere, so Hayabusa-2 has given us so much more than close-up images of asteroid (162173) Ryugu.

We can convince ourselves of this with the announcement made via an article by an international team of researchers led by Jens Barosch and Larry Nittler of the Carnegie Institution for Science published in astrophysical journal letters.

The members of this team made it known that they discovered nothing less than presolar grains in the samples brought back by Hayabusa-2.

A key to the cycle of stars in the Milky Way

With this we refer to materials Crystals and amorphous solids
Scaling…” data-image=”” data-url=”https:// .com/sciences/definitions/solid-chemistry-15332/” data-more=”Read more”>solid that have condensed into grains, not recent studies tend to show that brown dwarfs, even the smallest celestial objects called “planemos,” are also surrounded by a protoplanetary disk.” data-url=” https://news .Google. com/sciences/definitions/universe-disque-protoplanetaire-4444/” data-more=”Read the definition”>protoplanetary disk of gas and dust in the process of cooling around the young Sun, about 4.5 to 4.6 billion years ago, but even before the birth of the Sun, in the atmospheres stellarstars existing before him and from which they were expelled at the end of their lives to find themselves in the interstellar medium, then in the protosolar nebula at the origin of the Solar System.

Remember that there is an actual stellar cycle in From Earth, we can only observe a cross section…” data-image=” /7 /777b761907_120668_voie-lactee-galaxie.jpg” data-url=”” data-more=”Read more”>Milky Way which causes it to evolve chemically with a growing enrichment of the interstellar medium in heavy elements. In this environment, molecular and dusty clouds, dense and cold, gravitationally collapse, destabilized under the effect of a Pressurewhether they are density waves in the arms of our Galaxy or by the shock wave from the explosion of an Extract from…” data-image=” /a940132305_50034136_supernova1987a.jpg” data-url=”” data-more=”Read More”>supernova.

As the clouds collapse, they fragment giving rise to nurseries of stars, some of which will evolve very rapidly by exploding into supernovae, injecting new heavy elements into the cloud where star formation continues. The explosion of one of these stars, nicknamed coatcaused the When this collapse refers to coherent rocks, we can also speak of a rock slide.
The result of this…” data-image=” ” data-url=”” data-more=”Read More”>to collapse from the protosolar cloud where our Sun was born. More generally, stars at the end of their lives will return the matter that formed them to the interstellar medium, but with new elements, an environment in which new stars will be born for the same reasons.

This is what makes Jens Barosch say that, in the case of the findings in the Ryugu samples, ” different types of presolar grains come from different types of stars and stellar processes, which we can identify from their isotopic signatures. The possibility of identifying and studying these grains in the laboratory can help us understand the phenomena astrophysics that shaped our Solar System, as well as other cosmic objects “.

In fact, cosmochemists can, with sophisticated microanalytical instruments, measure the abundance of various isotopic nuclei of an element that differ in their number of neutrons, and compare them with those measured in carbonaceous chondrites that hit Earth.

On this subject, and again in a press release from the Carnegie Institution for ScienceLarry Nittler explains that “ the compositions and abundance of presolar grains we found in the Ryugu samples are similar to those we have previously found in carbonaceous chondrites. This gives us a more complete picture of our Solar System’s formation processes that can inform future models and experiments on samples from Hayabusa2, as well as other meteorites. “.

In this video, Philip Heck talks about his research on presolar grains, minerals that formed before the birth of our solar system. ” Science at FMNH » is a series of podcasts and videos that explores the behind-the-scenes science, collections, and research at field museum Chicago For a fairly accurate French translation, click on the white rectangle at the bottom right. Then the English subtitles should appear. Then click on the nut to the right of the rectangle, then on “Subtitles” and finally on “Auto translate”. Choose “French”. © field museum

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