Astronomers around the world are trying to track down a small, fast-moving object that is zipping through our solar system.

Is a comet? An asteroid? NASA’s not sure. The space agency doesn’t even know where it came from, but it’s not behaving like the local space rocks and that means it may not be from our solar system.

If that’s confirmed, NASA says “it would be the first interstellar object to be observed and confirmed by astronomers.”