Interstellar Interlopers Like 'Oumuamua' and 'Borisov' Are Much More Common Than Thought. Right now, in Neptune's orbit alone, there could be about 10,000 interstellar objects.

Researchers are working to answer basic questions about these extraterrestrial objects, such as where they come from and how they end up roaming the galaxy. The intruders could also provide a new way to probe the characteristics of distant planetary systems. But first, astronomers need to find more. “At the moment we are a little behind,” says planetary scientist David Jewitt of UCLA.