A team of researchers from different institutions coordinated by the astrogeobiologist Birger Schmitz, from the University of Lund, in Sweden, has discovered a new type of meteorite unknown until now on Earth. The space rock, according to these scientists in an article published in the journal Nature Communications , was found in a quarry in that Nordic country, and could have originated after a violent collision that occurred in the asteroid belt, a region of the Solar System located between the orbits of Mars and Jupiter.
“Not one of the more than 50,000 meteorites that have been recovered throughout history looks like this,” says Qing-zhu Yin, an expert in geochemistry and planetary sciences at the University of California, Davis, who has collaborated in the study. In it, its authors point out that the meteorite, called Öst 65, formed 470 million years ago and traveled through space for another million years before hitting Earth. To determine this, they measured the time it was exposed to cosmic rays, a cascade of subatomic particles that floods space.
Numerous chondrites, fairly common non-metallic meteorites of the same age, have been found in the quarry, suggesting that they were part of one of the objects that collided at that time. However, it is unclear what he did it against. What remains of the Öst 65 specimen, barely 10 centimeters long, is an amalgam of more or less hard minerals, especially chromites and spinels, but it has certain isotopic and chemical peculiarities that make it unique.
The researchers believe that it could be the first sample of an “extinct” meteorite , that is, a variety of space rock whose existence would have been overlooked because the original would have been practically vaporized in different collisions. Of course, they also point out that it is possible that some remains still survive in space.
Apparently, a series of collisions between asteroids caused a meteor shower on the planet during the Ordovician period, between 485 and 443 million years ago. Geologists estimate that about a hundred times more of these bodies fell on Earth then than today.
In fact, these researchers think that this phenomenon could have affected the development of life , since it coincides in time with a moment of great diversification of fauna. “This gives us an idea of to what extent the processes that occur in the Solar System are interconnected in time and space; a fortuitous collision in the asteroid belt could have marked the evolutionary path of many species on our planet ”, Yin points out.
Image: Qing-zhu Yin / UC Davis
