Une célèbre image de la Terre et de ses océans prise par les astronautes d'Apollo 17. © Nasa

The water of the oceans would come from asteroids according to a new study

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[EN VIDÉO] The 42 largest asteroids in the Main Belt scanned by the VLT
The VLT’s Sphere instrument has observed the largest Main Belt asteroids between Mars and Jupiter.

The missions The Apollo space program
Apollo is an American space program for human exploration of the Moon decided by American President John Fitzgerald Kennedy in 1961.
The objective of the…” data-image=”https://cdn.futura-sciences.com/buildsv6/images/midioriginal/b/7/5/b7563ef6d1_50084103_apollo11.jpg” data-url=”https:/ /news.google.com/sciences/definitions/universe-apollo-3743/” data-more=”Read more”>Apollo and the interplanetary probes launched during the 1970s made it possible to broadly confirm a scenario elaborated in the preceding decades giving rise to planets and comets in a Recent studies tend to prove that brown dwarfs, even even smaller celestial objects called “planemos”, are also surrounded by a protoplanetary disk.” data-url=”https://news.google.com /sciences/definitions/universe-protoplanetary-disk-4444/” data-more=”Read the definition”>protoplanetary disc rich in gas and dust surrounding a young The Sun is the closest star to Earth, from which it is about 150 million kilometers away. The Sun is located 8.5 kparsecs from the center of the Milky Way. In star classification, the sun is a G2 type star.
The mass…” data-image=”https://cdn.futura-sciences.com/buildsv6/images/midioriginal/1/d/9/1d9cd1d45f_50034577_eruption.jpg” data-url=”https://news. google.com/sciences/definitions/univers-soleil-3727/” data-more=”Read more”>Sun about 4.56 billion years ago.

This scenario brings out and grows the rocky planets like the earth, Mercury or March by accretionwith a bombardment ofasteroids and comets, traces of which can still be found in the form of lunar craters. The water in the oceans on Earth must come from this bombardment, but for decades the debate has continued regarding the exact nature of the small celestial bodies responsible for this contribution. In other words, does the water mainly come from comets or asteroids?

Futura has devoted many articles to this debate and today a new piece has just been brought to it via an article in Nature Astronomy. It reports certain results from the analyzes of samples of organic matter, nitrogenous matter, etc.
There are different families like:

organic matter, which constitutes living beings (animals or plants) or…” data-image=”https://cdn.futura-sciences.com/buildsv6/images/midioriginal/e/7/0/e70ccaaf4a_91935_matiere. jpg” data-url=”https://news.google.com/sciences/definitions/matiere-matiere-15841/” data-more=”Read more”>matter reported to Earth at the end of 2020 by the Japanese probe Hayabusa-2. These samples come from the asteroid Ryugu (“Dragon Palace”, in Japanese), a member of the Apollo asteroid family, of type C because of composition close to the chondrites found on Earth, and which is located more than 300 million kilometers from our Planet.

Less than 900 meters in diameter, the study of its samples confirmed that it contained original material dating from the formation of the Solar system and which had been little altered despite traces of heating and water circulation liquid but whose temperature must not have exceeded 30°C.

Hydrogen isotopes as cosmogonic tracers

Cosmochemists studying the samples of Ryugu explain today that the analyzes of abundances of hydrogen and nitrogen isotopes point out once again the relationship between the water of asteroids and that of the oceans on Earth.

To understand what it is, just remember that there are naturally two types of water, one, ordinary, is made ofatoms General
Symbol: H Atomic number:…” data-image=”https://cdn.futura-sciences.com/buildsv6/images/midioriginal/3/8/8/38807f95a1_50010101_equinoxprom-eit-big.jpg” data-url =”https://news.google.com/sciences/definitions/chemistry-hydrogen-14495/” data-more=”Read more”>hydrogen H with a single proton for core; the other, called heavy, is made of deuterium D atoms, so a nucleus with a proton and a It is not an elementary particle, any more than the proton, because it is composed of…” data- image=”https://cdn.futura-sciences.com/buildsv6/images/midioriginal/1/5/5/15590279f6_71819_atome.jpg” data-url=”https://news.google.com/sciences/definitions/ physics-neutron-3498/” data-more=”Read more”>neutron.

A fraction of the water on Earth is made up of the so-called single covalent bond…” data-image=”https://cdn.futura-sciences.com/buildsv6/images/midioriginal/d/0/e/d0e3dc7e1e_76472_molecule .jpg” data-url=”https://news.google.com/sciences/definitions/chemistry-molecule-783/” data-more=”Read more”>molecules containing deuterium instead of a hydrogen atom. We can thus define a D/H isotopic ratio which is a tracer of the origin of ocean water in cosmochemistry.

By comparing this relationship with that found in meteorites and comets, it is therefore possible to determine which were the parents of the water of the oceans. For years, the thesis of an origin of this water by volcanic outgassing of the young Earth has been abandoned and the pendulum has not stopped tilting alternately either on the side of the comets or on the side of the meteorites.

The study of meteorites on Earth – which mainly come from the main asteroid belt – has made it possible to establish that on average, the D/H ratio was of the order of 140 ppm whereas this ratio, when determined in certain comets, was between 150 and 300 ppm. As on Earth it is around 150 ppm, the cometary hypothesis has been disproved, or at the very least, comets would not be, by far, the main source of water on Earth.

Ryugu’s analyzes therefore support the asteroid hypothesis.

The Solar System is a laboratory for studying the formation of giant planets and the origin of Life that can be used in conjunction with the rest of the observable Universe for the same purpose. MOJO: Modeling the Origin of JOvian planets, i.e. modeling the origin of the Jovian planets, is a research project that has resulted in a series of videos presenting the theory of the origin of the Solar System and in particular of the gas giants by two specialists renowned, Alessandro Morbidelli and Sean Raymond. To obtain a fairly accurate French translation, click on the white rectangle at the bottom right. The English subtitles should then appear. Then click on the nut to the right of the rectangle, then on “Subtitles” and finally on “Translate automatically”. Choose “French” © Laurence Honnorat

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