Science Reporting

Vesta was hit by a big rock 4.5 billion years ago

Vesta is one of the space bodies included in the asteroid belt, one of the largest with an average diameter of 525 miles (it is the second most massive body after Ceres). Discovered by Heinrich Wilhelm Olbers in 1807, it is a quite interesting body also because it is the brightest asteroid visible from Earth.

A group of researchers from the Tokyo Institute of Technology and the National Institute for Polar Research and ETH Zurich discovered that this large asteroid suffered a massive hit-and-run collision 4.52 billion years ago that profoundly influenced its evolutionary history. Among other things, this same impact would help explain the asymmetrical shape of the asteroid.

In the study, published in Nature Geoscience, it is also stressed that this asteroid has an original structure with its crust, its mantle and its metal core, a structure quite similar to the Earth but unusual for the asteroids themselves.

Examining a rare mineral called zircon found in the mesosiderites, the team, with unprecedented precision, established that 4558.5 million years ago (with a margin of error of 2.1 million years) the crust had begun to form and that 4525.4 million years ago (with a margin of error of 850,000 years) there was a strong metal silicate mixing event.

These two events would testify to the impact with another asteroid that occurred in the northern hemisphere of Vesta, an impact that was probably the cause of the same formation of the thick crust that was then observed during the Dawn mission of NASA.