Asteroid dust helps to understand the evolution of organics in space

Asteroid dust helps to understand the evolution of organics in space
Asteroid dust helps to understand the evolution of organics in space
Anonim

Scientists have long known that a number of ingredients are needed to sustain life, the main of which are carbon and water. In the past few years, both of these ingredients have been found on the surfaces of giant asteroids and other celestial bodies.

However, until now, science has not had convincing facts based on the study of samples of extraterrestrial origin, which would illustrate how and when organic matter was formed on the surfaces of cosmic stones thrown into our solar system.

In the new study, a team led by Dr. Q. H. S. Chan of Royal Holloway University, UK, analyzed extraterrestrial dust samples taken from the surface of the asteroid Itokawa by the Japanese Hayabusa probe. These particles were carefully protected by scientists from pollution of terrestrial origin, so the organic matter found on them could only be formed in space.

Chen's team examined in detail one dust particle called Amazon (see photo). This unofficial name was given to the particle due to the fact that in shape it is very similar to the South American continent, along which the famous river of the same name flows. The isotopic composition of the organic material found on this particle confirmed that organic matter is of extraterrestrial origin.

Chen and his colleagues showed that all organic compounds found on the surface of Amazon dust particles can be divided into endogenous (formed on the Itokawa asteroid itself) and exogenous (delivered to the asteroid's surface). Scientists were able to make such a conclusion, since some of the organic inclusions were graphitized. This degree of graphitization can occur when organic substances are heated to temperatures of the order of 600 degrees Celsius. Organic samples of these two different varieties were located on the surface of the dust particle at a distance of only 10 micrometers from each other.

The fact that matter on the asteroid Itokawa was heated to a temperature of 600 degrees Celsius may indicate that Itokawa was part of a larger asteroid with a diameter of at least 40 kilometers, which once experienced a powerful collision and split into fragments, some of which again stuck together among themselves and formed the asteroid Itokawa, the authors note.

The heated organic matter could come from the very hot bowels of the parent asteroid, while the unheated organic matter settled on the surface of the Itokawa asteroid later, as a result of the fall on the asteroid of carbonaceous meteorites or cosmic dust. A similar situation was observed with water - it was lost into space when heated, and then its reserves were replenished due to the delivery of exogenous water to the asteroid Itokawa, after the asteroid cooled down, Chen and his colleagues point out.

The work was published in Scientific Reports.

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