Mystery of interstellar visitor 'Oumuamua gets trickier
My pet theory (which is not intended to be taken too seriously) is that it is indeed a discarded light sail, and that light sail in particular was used to transport a Von Neumann probe which detached at some point after the object entered our solar system but before we first observed it. This detachment, in addition to leaving the sail tumbling, would have changed its trajectory, meaning our estimation of which direction the object originally came from is incorrect. In any case, the probe is now busy replicating, perhaps on the surface of Mercury. In a few years an army of robots will launch from there and invade the rest of the solar system!<p>Realistically, though, it's too much of a coincidence that such a probe would first arrive so soon after we gained the ability to conceive of it.