Two astronomers have discovered an asteroid in our solar system that, they claim, could be the first object to have an extra-solar origin.
Labelled Asteroid 2015 BZ509, the object has been in our solar system for some time and, as the name suggests, was spotted three years ago.
However, new studies - conducted by Helena Morais, a researcher at UNESP in Brazil, and Fathi Namouni, CNRS researcher at the Laboratoire J.-L Lagrange - suggest that it didn't originate here.
Published in the Monthly Notices of the Royal Astronomical Society journal, the findings were made via the researchers' calculations, which involved reconstructing its orbit by numerical simulation.
Migration of this kind is perfectly possible, since the original star cluster in which the Sun formed contained stars with their own planets and asteroids
Doing this, the scientists were able to go back 4.5 billion years in time to the birth of the Solar System. They found that 2015 BZ509 had always had a retrograde orbit, even in the earliest days of the Solar System, at a time when absolutely all the asteroids and planets orbited the Sun in the same direction.
This, they said, implies that 2015 BZ509 did not originate in our Solar System but must have formed in a neighbouring planetary system, before being 'captured' by Jupiter.
"Migration of this kind is perfectly possible, since the original star cluster in which the Sun formed contained stars with their own planets and asteroids.
"The close proximity of these stars, combined with the gravitational pull of the planets, may have allowed these planetary systems to attract, remove and capture asteroids from each other," the researchers explained.
While 2015 BZ509 is the first body in the Solar System identified as having an extrasolar origin, there could be many more, the researchers said.
They added that by understanding exactly when and how 2015 BZ509 (and other objects like it) migrated into the Solar System would offer us the ingredients needed for the emergence of life on Earth.
Cotton seedling freezes to death as Chang'e-4 shuts down for the Moon's 14-day lunar night
Fortnite easily out-earns PUBG, Assassin's Creed Odyssey and Red Dead Redemption 2 in 2018
Meteor showers as a service will be visible for about 100 kilometres in all directions
Saturn's rings only formed in the past 100 million years, suggests analysis of Cassini space probe data
New findings contradict conventional belief that Saturn's rings were formed along with the planet about 4.5 billion years ago