At the time of this writing, the scientific community has coalesced around the hypothesis that ‘Oumuamua was a comet, albeit a peculiar one. A virtue of this hypothesis is its familiarity. We have observed many comets whose trajectories deviated from paths shaped by the Sun’s gravity alone. We also know why that happens: in all cases, it is due to outgassing. But as I have just explained, ‘Oumuamua showed no outgassing. And yet it deviated.
