Late last year, our solar system received an unexpected visitor from interstellar space: The asteroid ‘Oumuamua that was discovered suddenly in October and then just as quickly disappeared, passing briefly through our solar system on the way to somewhere else. But now we have a better chance to study a visitor from beyond our solar system.
According to scientists from the Côte d’Azur Observatory and São Paulo State University, there’s at least one interstellar asteroid already here. They found an interstellar asteroid near the planet Jupiter, and unlike ‘Oumuamua, this asteroid is here to stay.
Asteroid 2015 BZ509 was discovered a few years ago by the Pan-STARRS sky survey, the same one that discovered ‘Oumuamua last year. This new asteroid, 2015 BZ509, is a pretty strange one because it orbits in retrograde—in the opposite direction as pretty much everything else in the solar system.