Interstellar Visitors Could Vanish in Space Before We Ever See Them. Here's Why
So far we know of only two interstellar objects (ISO) to visit our Solar System. They are Oumuamua and 2I/Borisov. Theres a third possible ISO named CNEOS 2014-01-08, and research suggests there should be many more.
Hong Minh Phan Aachen University Initiative For Interstellar Icy Interstellar Objects Cosmic Rays Milky Way
Source: sciencealert.com