Oumuamua illustration by Stuart Rankin Humans like to label things. In general, this works out for us. If you go to a furniture store and ask for a sofa, they will show you things multiple people can sit on that are clearly sofas. Ask for a chair, and they will show you seating for one in a variety of styles. The problem is, there are things out there, like my Ikea hack of not-a-chair-or-sofa that defies classification. In our solar system, we don’t … or at least we don’t yet… have solitary orbiting sofas and chairs. What we do have are comets and asteroids.  Asteroids, like the...