  1I/`Oumuamua and 2I/Borisov are the first macroscopic interstellar objects to
be detected in the solar system. Their discovery has triggered a tsunami of
scientific interest regarding the physical properties, dynamics and origin of
the so-called interstellar interloper population. While it is clear that a deep
understanding of these issues cannot be reached from a sample of just two
bodies, the emergence of this new field of astronomical study is particularly
fascinating, with ramifications from planetary science to galactic dynamics.
