There were a lot of humans on Earth. People suspected that it would probably get to more than it could hold.

[He would ask about gravity, but the talking planet is strange enough and he's not sure that Wander would actually know how everything worked there, technically. Though he's vaguely aware that different universes come from different sorts of laws and this one... adjusts... a little bit.]

Sometimes lonely people take a while to learn how to act around others. Planets included.