I understand the difference between comets, asteroids, and meteoroids. I was just reading about asteroids recently, and it occurred to me that when I read anything about these three types of objects the implicit (and sometime explicit) assumption is that they only apply to things that orbit the sun. I realize that this is probably because we are not (yet) able to detect them elsewhere. At least, not that I know of. From what I understand, asteroids always refer to things in the asteroid belt. Comets refer to things that come from the Kuiper belt or Oort cloud. Meteoroids I'm not sure about other than they refer to things smaller than asteroids I believe. I have tried to find the "official" definitions for these things. And by that I mean what an astronomer would call them, but I keep finding conflicting information. What are the official definitions of comet, asteroid, and meteoroid? Are there different names for space rocks that are like these three, but that orbit other stars, or that don't orbit a star at all?