Primitive meteorites, known as carbonaceous chondrites, are fragments of asteroids that have not undergone significant fusion or differentiation. Their chemical composition faithfully reflects that of materials present in the primitive solar system, with chemical ratios very similar to those observed in the Sun’s photosphere. However, after studying nearly 8000 meteorite samples, the findings are as clear as they are surprising : carbonaceous meteorites make up only 4% of the bodies that have fallen to Earth.
Why is this so ? We invite you to read the Paris Observatory press release, and for the more motivated, the article itself, to understand how the study answers this question. There are two main explanations for this phenomenon. The first concerns the thermal fragmentation that takes place when they pass close to the Sun, and the second would be filtering by the Earth’s atmosphere, which is particularly effective on carbon bodies because they are more fragile.
This is the kind of study that will take us a step closer to understanding the formation of bodies in planetary systems, both in our own solar system and in others !
You can find the Paris Observatory press release and the link to the article.
