Five years ago a very strange objectmaybe a thousand feet long, oblong, shiny and faststreaked across space, tens of millions of miles from Earth. Its course and speed indicated it had come from outside the solar system. A visitor from another star. Astronomers dubbed the thing OumuamuaHawaiian for scoutand started arguing about it. On one side are an overwhelming majority of scientists who dont know what Oumuamua is, but arent willing...