On Distinguishing Interstellar Objects Like `Oumuamua From Products of Solar System Scattering

Schneider (2018) explored the possibility that 'Oumuamua is a Solar System object, and concluded that if it is, it must have been scattered by “another, yet unknown planet.” I provide an extremely conservative upper limit on post-scattering velocities in the Solar System to show that 'Oumuamua is moving far to quickly to be the result of any hypothetical single scattering event between any bound Solar System objects within 21 au (a distance within which our understanding of objects capable of scattering 'Oumuamua is presumably complete).