A GROUP of 19 “alien” asteroids lurking between Jupiter and Neptune may have come from another star system, according to scientists. The findings come more than two years after astronomers spotted the first interstellar visitor, the asteroid known as ‘Oumuamua.’ According to the scientists, unlike ‘Oumuamua, these space rocks have been orbiting the Sun for more than 4.5billion years, since the birth of the Solar System. The asteroids, part of a group of space objects known as Centaurs, may have been orbiting another star billions of years ago when stars were much closer to each other.
Fathi Namouni, of Observatoire de la Cote d’Azur in France and lead author of the study, said: “The close proximity of the stars meant that they felt each other’s gravity much more strongly in those early days than they do today. This enabled asteroids to be pulled from one star system to another.”
Dr. Namouni and co-author Maria Helena Morais, of the Universidade Estadual Paulista in Brazil, ran computer simulations going back in time to the days when the Solar System was still forming. The simulations revealed the asteroids were orbiting the Sun on a plane perpendicular to planetary motion at that time. These objects were also found to be located far from the disc that gave rise to the planets and other asteroids within the Solar System. These two observations indicate the asteroids were captured from another stellar system, the researchers said. –The Sun