So something like you can only initially go to the moon or Mars from a city with a spaceport (or NASA). When on the city you get a button that says "Launch" and then it brings up a list of possible colonies you can go to. Each would take a different number of turns to arrive at. When you are first going to the moon or Mars you will arrive at a random location. And until you have set up a spaceport on either the moon or Mars you will not beable to arrive directly at on of their colonies. The Galactic map however always has you start out at Sol. Sol cannot be claimed, however other star systems can. When leaving out solar system you will select that from the launch menu. However rather than getting a free ride to another star you must actually travel across space to your other colonies. However I suspect it will at least take some turns initially to go from either Earth, the moon or Mars to the Galactic map. Thus your propulsion method is important for reducing launch times and movement on the Galactic map.