Scientists at São Paulo State University's Institute of Geosciences and Exact Sciences (IGCE-UNESP) in Rio Claro, Brazil, have recently spotted 19 asteroids of interstellar origin. These asteroids are classified as Centaurs, which are outer Solar System objects that revolve around the Sun in the region between the orbits of Jupiter and Neptune.
The study titled An interstellar origin for high-inclination Centaurs was supported by FAPESP and has been published in the Royal Astronomical Society's Monthly Notices.
According to the study, when the Solar System formed 4.5 billion years ago in a stellar nursery, it comprised its systems of planets and asteroids. Some starts were close enough to each other to facilitate strong gravitational interactions. Due to these interactions, an exchange of material among the systems took place, reported.
"Some objects now in the Solar System must, therefore, have formed around other stars. Until recently, however, we couldn't distinguish between captured interstellar objects and objects that formed around the Sun. The first identification was made by us in 2018," said Maria Helena Moreira Morais, one of the two co-authors.
The first space rock that the scientists discovered was the asteroid 514107 Ka'epaoka'awela. The name of the asteroid is Hawaiian and loosely translates to "mischievous opposite-moving companion of Jupiter".
The study reveals that the Centaurs have highly inclined orbits with respect to the orbital plane of the planets. It also divulged that the space rocks and planets which arose in the Solar System were produced from a thin disk of gas and dust that orbited the sun.
According to researchers, celestial bodies and objects that were formed in the solar system moved in the plane of the disk 4.5 billion years ago. If this was the case, it should have also been true for Centaurs.
"However, our simulation showed that 4.5 billion years ago, these objects revolved around the Sun in orbits perpendicular to the disk's plane. In addition, they did so in a region distant from the gravitational effects of the original disk," Morais said.