Not at all a dumb question! The argument goes that we haven't had powerful-enough telescopes (or enough dedicated observing time) to image it. Not everyone buy

Not at all a dumb question! The argument goes that we haven't had powerful-enough telescopes (or enough dedicated observing time) to image it. Not everyone buys this; some people think it does not exist, and the perturbed orbits of Kuiper Belt objects are just a random fluke.