‘IMMIGRANT’ ASTEROID FOUND IN JUPITER’S ORBIT
Meet the Solar System’s first-known permanent immigrant. A team of international researchers have located an asteroid nestled in Jupiter’s orbit that started life in another solar system.
Dubbed (514107) 2015 BZ509, or BZ for short, the asteroid was found in a retrograde orbit, meaning that it moves around the Sun in the opposite direction to the other planets.
When the team ran simulations to trace the location of BZ back to the birth of our Solar System, 4.5 billion years ago when the era of planet formation ended, they found the asteroid has always moved in this way. This means that BZ could not have been there originally and must have been captured from another system.
“Asteroid immigration from other star systems occurs because the Sun initially formed in a tightly-packed star cluster, where every star had its own system of planets and asteroids,” said Dr Helena Morais of Brazil’s Universidade Estadual Paulista, who took part in the research. “The close proximity of the stars, aided by the gravitational forces of the planets, help these systems attract, remove and capture asteroids from one another.”
Understanding how and when BZ settled in the young Solar System could provide clues about the conditions when the planets were first being formed. It could offer insights into Earth’s early environment and potentially the arrival of components necessary for the appearance of life on Earth.