In a sense, it's a matter of luck. The asteroid travels on alternating sides of Jupiter, with one pass reeling it in while another pushes it outward -- it's in just the right trajectory to maintain a yin-yang balance. This is a stable orbit, too, as scientists estimate that the asteroid has been locked to this path for about 1 million years.

The finding isn't completely shocking given the scale of the cosmos (something like this was bound to crop up), but it's still important. It could help shed new light on how orbits work, and it's a friendly reminder that space doesn't always conform to expectations.