Even so, I would think that having all of them off planet Earth would be preferable to some on it and some off. Inside the Sun, inside some of the ice-moons of the gas giants, and on various random trajectories out of the solar system (not strapped to a probe whose telemetry we know very well, for goodness’ sake) would seem to be optimal. Of course this all depends on Voldy’s actual ability to put them there.
Then there’s the whole issue of traps/alarms. Trapping is probably not worthwhile if you’re hiding in highly-inaccessible places, since if your enemy can get there she’s pretty powerful already, and the traps could easily draw attention. (On the other hand, if you have something as crazy as the Big Bowl o’ Poison one, where the enemy somehow is forced to injure himself to get the horcrux, with absolutely no way around it, then it could be worthwhile.) (Silent) alarms, on the other hand, seem absolutely essential: you must know if one of your horcruces has been touched, let alone destroyed, so you can take appropriate steps.
Even so, I would think that having all of them off planet Earth would be preferable to some on it and some off. Inside the Sun, inside some of the ice-moons of the gas giants, and on various random trajectories out of the solar system (not strapped to a probe whose telemetry we know very well, for goodness’ sake) would seem to be optimal. Of course this all depends on Voldy’s actual ability to put them there.
Then there’s the whole issue of traps/alarms. Trapping is probably not worthwhile if you’re hiding in highly-inaccessible places, since if your enemy can get there she’s pretty powerful already, and the traps could easily draw attention. (On the other hand, if you have something as crazy as the Big Bowl o’ Poison one, where the enemy somehow is forced to injure himself to get the horcrux, with absolutely no way around it, then it could be worthwhile.) (Silent) alarms, on the other hand, seem absolutely essential: you must know if one of your horcruces has been touched, let alone destroyed, so you can take appropriate steps.