Samples from asteroid Ryugu begin to reveal their secrets

Exactly a year ago, the Hayabusa-2 probe brought back samples from the asteroid Ryugu. The first analysis of this material reveals unexpected information, questioning our knowledge of the history of the Solar System.

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the inspection Hayabusa-2, in class Around (162173) ryugu From June 2018 to November 2019, we were informed on December 5, 2020 samples its small star, This week from them First articles aboutanalysis of this material Posted in nature astronomy,

Ryugu is a type C asteroid that is rocky and dark in colour. rich in carbon and water. chondrite carbonized, Meteorite Who will come Such asteroids exhibit a number of features indicating that they have been replaced by liquids. these bodies, which were trained on the edge of asteroid belt, which contained ice mixed with rock. chunk of ice floor, which produced Minerals Clay and carbonate (salts).

one of the mission objectives Hayabusa-2 was to study the link between C-type asteroids and chondrite This is important because carbonaceous chondrites are probably the kind of objects that have brought water And organic compounds on earth, allows life to emerge there,

less dense dust than expected

Hayabusa-2 Collected 5.4 grams dust, equal to one teaspoon. This may not sound like a lot, but it is still several thousand grains that can be analyzed individually. As a reminder, the initial aim was to take 0.1 g. Since these samples are irreplaceable, analysis began with non-invasive and non-destructive observations and is now followed by complex measurements that require handling and preparation of samples.

large mass The apparent was measured by Ryugu Hayabusa-2 About 1.190 kg/m. Feather3, This lower value was expected because the asteroid was assigned a . It is believed pile of rubble gathered after Collision of a larger body and therefore is a porosity High. On the other hand, what was the surprise when the density of material The collected turned out to be almost as little, about 1,300 kg/m.3 , The grain must be compacted in the collection process, as well as shaking during Transit and enteringAtmosphere, This density is also much lower than that of the presumed meteorites of Ryugu.

The authors have put forward two additional reasons for this. Meteorites that ended up on Earth were first ejected by colliding with their parent asteroid. Unlike the contents of Ryugu, which were protected by its capsule, their dive into the earth’s atmosphere caused their fragmentation. Thus, meteorites that hit Earth have experienced at least one additional event that may have reduced their porosity. Ryugu may also contain more low-density materials, such as organic molecules, that such meteorites. This is important because it implies that the Ryugu material retained carbonaceous material that we have not been able to study before. This should allow us to learn more about essential building blocks of life,

Preliminary Grain Analysis

The composition of several ryugu grains was also assessed by spectroscopy. It is not the most common technique for initial composition analysis, but has been used because it is non-destructive, does not require sample preparation, and allows direct comparison of grains with measurements at the body surface. Hayabusa-2,

Not surprisingly the grain and surface asteroid Both with the same water footprint (as hydroxide, OH) have very similar spectra. A more detailed laboratory analysis than the wavelength measured on the asteroid revealed additional features, including the identification of a . was made as coming from nitrogen component Which, according to the authors, could come from ammonium-rich soil minerals or nitrogen-rich organic matter. However, a different analytical technique would be needed to determine the abundance of organic compounds in samples.

The authors also found a giant grain of carbonate about half a millimeter long that could be rich in ironThis type of meteorite is very characteristic.

Although this is a preliminary analysis, these papers suggest that Ryugu’s material is primitive and significantly different from known meteorites, raising the question to what extent the meteorites are representative of asteroids. It may change some aspect of our outlookhistory of the solar system,

what you should remember

  • Ryugu samples are less dense than expected. This would indicate that ryugu contains carbonaceous material.
  • Grains also contain water and a nitrogen component.
  • Ryugu’s material is primitive and different from known meteorites, questioning whether meteorites are representative of asteroids.

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