A new study found that rare meteorites that are made up of a mixture of iron and stone were likely to be formed at the time when the brightest asteroid Vesta had gone through a huge impact.
The researchers argued that this impact had taken place 4.5 billions of years back when young Vesta collided with a rock that was tenth of Vesta’s size and the rock penetrated into the core of Vesta.
The lead author of the study Makiko Haba who is a planetary scientist, said the meteorites that resulted from this have allowed the researchers to get a detailed biography of the asteroid.
Researchers now suggest that these meteorites formed following the colossal impact which the second largest asteroid Vesta had gone through in the initial time of solar system. Haba said that they propose a fresh history of evolution of Vesta. Researchers had analyzed mesosiderites unearthed from Iowa, northwest Africa, Chile from 1861-2014.
He said that they had noted that the zircon crystals from the meteorites have likely been formed when the mesosiderites metals were molten. The crystals’ features and the meteorites’ metals have suggested that the materials have mixed in the asteroid’s molten core for 330 miles, matching Vesta.
Haba’s team next analyzed two dozen crystals of zircon that was extracted out of mesosiderites.
After examining the lead isotopes’ levels and that of uranium in the zircons, the team concluded that the meteorites’ silicates were formed 4.55 billions of years ago and metals and silicates mixed 4.52 billions of years ago. They said that after Vesta formed to separate into mantle, crust, and core layers, a rock smashed into it. This collision exploded a crater into the northern hemisphere of Vesta. The debris made up the three layers of Vesta and fell back on the asteroid on the southern hemisphere of Vesta. This explains the thick crust that NASA’s spacecraft detected at the south pole of Vesta.