Again I don't know for sure but I fear that predicting the position of Snoopy over a period of more than some months is impossible. There's not only the gravita

Again I don't know for sure but I fear that predicting the position of Snoopy over a period of more than some months is impossible. There's not only the gravitational interaction, but also the orientation dependent radiation pressure, tidal effects and gravity gradient torque. I would say the configuration space isn't just huge, it's probably all of the dynamically allowed space. I think the distance does matter. You have to observe an object ten times more distant a hundred times longer to receive the same amount of photons. If conservation laws dictate that it's still in the Earth-Moon system, that could mean significantly shorter observation times.