The next frontier is space, however previous candidates for a colony all fall short in at least one aspect and usually many;
>Mars
radiation, perchlorates, high energy to launch, limited energy sources.
>Europa
HIGH radiation, limited volatiles.
>titan
hydrogen cyanide clouds, far from metal resources ( iron is as rare as gold on titan)
>Venus
sulphuric acid clouds, high temps, can never land, no water.
and now i present to you Triton, the overlooked dark horse of space colonisation.
>triton
covered by tens to hundreds of metres of nitrogen ice which could be evaporated to give an atmosphere of 0.124 atm (vapour pressure of nitrogen) within a year by spreading dust from Proteus a moon with an albedo "as dark as asphalt" raising temps and sublimating all the nitrogen. this atmosphere is replenished by cryovolcanism and in the past maintained a thick atmosphere for hundreds of millions of years. there are heaps of hydrocarbon volatiles covering the surface too. with a gravity half that of the moon it would be a simply matter to run a gas mining operation on neptune which is the most helium 3 and deuterium concentrated body in the solar system. Triton is also inside the magnetic field of Neptune 25 times stronger magnetosphere than earth but no deadly radiation belts like Jupiter. Neptune is also very close to the kuiper belt which has 200 times the rock, iron and volatiles that the asteroid belt has. i present to you gentlemen that we "Titanform" Triton and conquer the fucking solar system with a monopoly on fusion fuel and mineral resources of the kuiper belt...