The Solar System has been here for a long time. So, when ’Oumuamua was spotted in 2017, it was almost a dead cert it wasn’t the only object from interstellar space to visit us over that 4.57 billion-year history. Then comet 2I/Borisov showed up last year. That basically clinched it.

But where are the rest of our interstellar visitors? We’ll probably find a few more flying in from the wilds in the coming years. And, according to new research, a whole bunch of interstellar asteroids have been hanging out right here in the Solar System for a very long time.

Based on how they move around the Sun, a team of researchers has identified 19 asteroids they think were captured from another star, way back when the Solar System was just a few million years old.