Personally I think colonizing planets is a waste of time. There's plenty of minerals and water in asteroids and other space junk, and they don't have large gravity wells to deal with. When it comes time to think about colonizing other star systems, it's going to take a really, really long time to get to them and we'll have little idea what their worlds are like. Seems to me it'd be better to work on colonizing space itself, because you'll pretty much have to anyways to make interstellar travel viable, and once you've done it there really isn't a good reason to live on a planet instead unless it happens to be a lot like earth.
Isn't a planet just a big spaceship with things built in? You can dig inside it for things, you don't need to capture asteroids, planets can travel through space and have a protective shield - the atmosphere, and Earth is already traveling at huge speeds, which are at very least on the level with the fastest spaceships we can currently make. Sure guiding a planet maybe harder than a spaceship made specifically for that purpose, but all the benefits of having resources right underneath, and planets are a proven space ships, with billions of years of testing, no man-made spaceship can match that for billions of years.
> planets can travel through space and have a protective shield - the atmosphere
Most worlds in our system don't have a significant atmosphere, most of those that do have too much of it. Like gravity, atmosphere also poses a problem for getting back to space.
> no man-made spaceship can match that for billions of years.
Not unmaintained, no, but if it was unmaintained that probably means everyone who lives there is dead anyway.
> Personally I think colonizing planets is a waste of time. There's plenty of minerals and water in asteroids and other space junk, and they don't have large gravity wells to deal with.
I more-or-less agree with this much, but the most suitable place to start learning to colonize space rocks is probably Phobos.
