Planet formation itself is a messy, stochastic process though. It could well be that there were multiple potential Planet 9s early in the solar system, and only one survived.
Fomalhaut b seems to be a reasonable analogue to Planet 9. Unfortunately, last time I checked we don't have a clue how it formed either.
Still, just because we don't fully understand planet formation isn't really a strike against the plausibility of it existing.
Planet formation itself is a messy, stochastic process though. It could well be that there were multiple potential Planet 9s early in the solar system, and only one survived.
ReplyDeleteFomalhaut b seems to be a reasonable analogue to Planet 9. Unfortunately, last time I checked we don't have a clue how it formed either.
Still, just because we don't fully understand planet formation isn't really a strike against the plausibility of it existing.