Mars, (or even teraforming the red planet) and Earth's Moon, of course, are both viable options. So are Mars' moons, Phobos and Deimos. ... Buta tiny, habitable world is, after all, still habitable. The rest of the planets, Jupiter, Saturn, Uranus, and Neptune, are all out. How...
: Gravity pulls the Earth in, andcentrifugal forceholds it out.* The centrifugal force on the Earth is just a result of the Earth moving in a curved path around the Sun. It doesn’t slow down because there isn’t any friction. After all, in space, there’s nothing to have friction ...