If anything I would say the Jovian system is fairly amenable to this kind of inter"planetary" civilization, insofar as the bodies are fairly close to each other and don't have too high delta-Vs to get from one to the other. There's also, ya know, four of them
If in the context of a story someone wanted to terraform the four moons you'd have a pretty good basis for a rocketpunk story.
A whoole terraformed moon will have insufficient insolation, but we can imagine paraterraformed Moons with a lot of big colonies under domes, with fusion powered artificial light. It may be intriguing to know if may be better building surface colony on the moons or using the moons as mines of raw matherial to build giant orbital space habitats: an habitat with 1 gee gravity may be best suited for humans, but in a future we can imagine radiation resistant GM people that not suffer of muscular atrophy and bone mass loss in microgravity and low gravit and can quickly adapt from 0 to 2.5 gee environments.
]]>What do you think of the fictional planet Polyphemus and satellite Pandora from the movie Avatar? How realistic is such a set up? http://james-camerons-avatar.wikia.com/wiki/Pandora
I've heard that gas giants are just about ruled out in the Alpha Centauri System, but in case there was one how realistic would that be? Polyphemus' radiation environment would probably be even more lethal than Jupiter as it sits right in the habitable zone Pandora has a gravity of about 0.8 of Earth.
http://james-camerons-avatar.wikia.com/wiki/Pandora
Avatar
Diameter 11447 km
Mass 0.72 Earths
Gravity 0.8 g
Atmospheric density 1.2 Earths
Surface pressure 0.9 atm
Very realistic: even the vortex is a phenomenon, due to interaction of ions current in the radiation belt with the magnetic field of the moon and the giant plantet, really observed between Juppiter and Io. On Pandora, the strong magnetic field of the vortex is the cause of superconductive levitation of unobteium rich rocks.
Polyphemus has a strong radiation belt like Juppiter but Pandora is protected by her own magnetic field and by her dense atmosphere, so life is possible.
The Twelve Colonies are situated within the star system Cyrannus, located some 2,000 light years from Kobol, where humanity presumedly first evolved. All in all, Cyrannus is a vast and complex system, comprised of four [4] stars: Helios Alpha, Helios Beta, Helios Gamma, and Helios Delta. Each star is orbited by its own family of planets and other astronomical bodies. The stars come together to form two binary systems (Alpha/Beta and Gamma/Delta). Both pairs of stars then orbit each other around a third, central barycenter every 546,892 years. Both binary systems are separated by 0.16 light years or 10,091 Stellar Units, shortened to SU (In this case, 1 SU being equal to the average distance between Helios Alpha and the barycenter of the Caprica-Gemenon binary, roughly 150 million km).
I'll bet that somewhere in the Milky Way Galaxy, there is a system like this, out of 100 billion stars, there might even be 12 Earthlike planets, but only Earthlike by the fact that each of them are in their respective star's habitable zone and each planet has approximately the same mass as the Earth, with diameters between 12,000 km and 13,000 km, but chances are, even if they had life on them, they wouldn't support human life without modification. The 12 Colonies System was designed for Rocketpunk.
]]>If in the context of a story someone wanted to terraform the four moons you'd have a pretty good basis for a rocketpunk story.
]]>But an M dwarf in the habitable zone of a star? You're going to be getting a lot of heat on it's planets, especially if they're orbiting close enough to do it in a day (HINT: there's a good chance they'd be molten). Maybe you could do it with a brown dwarf, though.
But with such a massive body, you should be able to stick significant masses at the L4 and L5 points and have them be stable. Say, a 40 jupiter mass brown dwarf, orbited by several terrestrial planets, and a Jovian in both L4 and L5, each orbited by terrestrial moons, and all of them be habitable. That's a lot of habitable worlds in one system, and the magnetic fields around their primaries offer lots of power for stuff like magbeam launch systems to go from sector to sector. Of course, in sector you'd be able to get away with chemical. Bonus points if the terrestrial worlds around the brown dwarf also have habitable moons.
An actually existing system that is somewhat similar is Epsilon Indi, with a binary brown dwarf system (separation ~2AU) that's 1,500AU away from a K-class star of similar metallicity to Sol (so, possibly terrestrial planets). It's a long journey between them, about 225 billion kilometers, but we should be able to manage it if we've got there in the first place. A few months travel at 0.1c, and it would take just over a week to receive news without an ansible.
]]>Even more unlikely on the scale of things would be an aerocapture type maneuver in the proplyd. Now just imagine getting to watch that!
]]>But a planet many times bigger than Jupiter might do much better.
Then there is our moon which did not form that way apparently. I have my own rogue notion of how it formed, I think it was condensed from the Earths spare material first as a wet object, and then was added to by rubble from impacts with the Earth. I think that is why there is evidence of magmatic water. I will not duke it out on that speculation however.
Then there is Triton, where it is thought it was captured. Most likely method, was that it was a binary object, and it's partner was either ejected, or impacted Neptune. So, maybe if you have a chaotic system forming with binary objects changing orbit, you could get a more substantial moon than if it
was a condensed moon, but it appears that that is not a common occurance.
I don't know, and given no additional information I'd say it's possible unless told otherwise. I've always been of the opinion that a very large portion of the habitable bodies out there are actually moons of gas giants or dual planet systems orbiting red dwarfs, simply because there are so many red dwarfs.
]]>http://james-camerons-avatar.wikia.com/wiki/Pandora
Avatar
Diameter 11447 km
Mass 0.72 Earths
Gravity 0.8 g
Atmospheric density 1.2 Earths
Surface pressure 0.9 atm