Asteroid is first ‘resident’ from outside our solar system

Hey bub, you’re going the wrong way.

The solar system’s first known “resident” that came from interstellar space — an asteroid orbiting backward around Jupiter — has been discovered, scientists announced Monday.

“How the asteroid came to move in this way while sharing Jupiter’s orbit has until now been a mystery,” said Fathi Namouni, lead author of the new study and a scientist at the University of Cote d’Azur in Nice, France.

The planets and most other objects in our solar system travel around the sun in the same direction. This asteroid is different — moving in the opposite direction in “retrograde” orbit.

The asteroid has the inelegant name of 2015 BZ509, indicating the year of its discovery.

Astronomers base their finding on extensive computer simulations that show the object has always orbited in reverse around the sun.

“If 2015 BZ509 were a native of our system, it should have had the same original direction as all of the other planets and asteroids, inherited from the cloud of gas and dust that formed them,” Namouni said.

The asteroid, about 2 miles across, arrived in our solar system shortly after it formed 4.5 billion years ago.

If it’s not native to our solar system, then where did it come from?

“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 Helena Morais, a study co-author from Sao Paulo State University in Brazil.

“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,” she said.