system
Given the following post, respond as if you're commenting on Reddit:
human
Can a 'moon' be bigger than the 'planet' it's orbiting? Can this last or will the smaller object soon switch to being the moon?

I know that Pluto and Charon are close in size and 'orbit' each other. Have any other planet / moon systems been found where the larger object orbits the smaller one? Is it even possible?
gpt
What's actually happening is that both objects are oribiting the common center of mass, which is somewhere between the centers of the two bodies. When one body is much more massive than the other (which tends to be the case), the center of mass is very close to the center of that body, and it will appear as if the smaller body is just orbiting the larger. When the two bodies are equally massive, they will orbit around the midpoint between them. You see this sometimes in binary stars.