interesting
Makes me think of planets like Pluto ahem... sub planets... ahem... well.. poor Pluto out there, with no real atmosphere... but yet I am led to believe that due to it's orbit it should retain a lot of atmosphere even with small gravity....
Titan is interesting too, being a satellite. Makes me think that the only reason why Titan has a think atmosphere is because of it's big brother Saturn. We already know how much a satellite influences the planet it orbits around, and we know that a satellite is influenced by it's planet... Maybe the only reason why Titan has such a think atmosphere is ONLY because of Saturns particular form...