Many asteroids could be remnants of five destroyed worlds, say scientists

At first, the solar system was little more than a cloud of dust and gas. Then cold temperatures shattered the center of the cloud, forming the sun. The fledgling star is lit with nuclear fusion, sending light and heat into the rotating circumstellar disk. Soon, this material melted into gaseous planets, ice giants and rocky worlds, creating the solar system we know today.

For years, asteroids were considered as the remnants of planetary formation. and who were drawn into the crowded belt of rocky remains that surrounds the sun between Mars and Jupiter.

But according to a study published Monday in the journal Nature Astronomy, these worlds were also pieces of worlds. A large majority of the half million bodies in the inner asteroid belt may actually be shrapnel from five parent bodies called "planetesimals," say the scientists. But the entangled orbits of these lost worlds meant that they were doomed to collide, producing fragments that also collided, producing even more fragments in a cataclysmic cascade that lasted for over 4 billion years. years.

A "mystery" of the asteroid belt, said Katherine Kretke, a global scientist at the Southwestern Research Institute who was not involved in the project. study. It could also help solve a debate about the formation of the eight planets – including the Earth.

"I find it really exciting that we can go back in time and potentially see what components have built our solar system. "If we can go back in time and see the asteroid belt created by these great planetesimals, it tells us something very definitive about the circumstances that shaped our own planet."

Lead author of the study, University of Florida astrologer Stanley Dermott did not necessarily seek to probe a mystery of solar system formation.He and his colleagues were examining data on the dynamics of the body in the inner asteroid belt in the hope of understanding what makes an object leave the belt – and potentially fly to the Earth. (For those who worry about collisions d & # 39; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; Asteroids, rest badured that Dermott is still studying this issue.)

But when Dermott began to look through a database of objects close to Earth, he noticed something strange about big asteroids: their o were inclined, or inclined, with respect to the plan of the rest of the solar system.

"We could not think of forces acting to produce this distribution," Dermott said. On the other hand, "if a big asteroid is broken and it has a steep tilt, then these fragments have this same tilt."

Scientists have already known that about half of the asteroids in the inner belt belong to five "families". "But Dermott and his colleagues say that their badysis suggests that the number is as high as 85%."

This discovery corresponds to other observations of the asteroid belt, says David Nesvorny, a planet scientist at SWRI who was not involved in Dermott's study Asteroids that are thought to belong to the same family tend to form groups in orbit and have similar chemical compositions.