Hi All

Gary wrote...

I'm partial to the theory that Pluto, Charon and Triton came from the same parent Kuiper belt object (the orbital mechanics of Neptune's moon are very odd).

[...The two original KBOs certainly interacted. I think proto-Triton smacked into Pluto-Charon, which gained enough angular momentum to fission.]

Titan is a really weird planet. Look at the atmospheric scale height for Titan. With Titan there is a low gravitational parameter coupled with a remarkably dense atmosphere. It's a perfect planet for doing aerocapture (provided the CN problem doesn't get out of hand).

[...from an orbiting mothership the re-entry speed would be pretty damn low - JP Aerospace's Orbiter airships would actually work on Titan because the orbital velocity is so low and the atmosphere has a very shallow gradient.]

Titan almost certainly has a rocky core. However there's a lot of funky stuff around that core, e.g. ice, tar, liquid methane, you name it.

Gary

[I think ammoniated tarry sludge sounds like a good place for spawning some weird life forms if there's enough energy flux passing through it from the silicates' radionuclides and tidal forces. In a few billennia the brightening Sun might cause the near-surface volatiles to pump up the atmosphere by a few bars raising the surface temperature close to the melting point of ammonia... so who knows? Perhaps a Second Genesis by 200 million AD?]

Adam