NB : Abandoning a colony also means losing all the stuff you built/moves there.
I made a similar mistake trying to set a colony on Titan. The experimet proves to be far too expensive, as Titan did not concealed any interesting minerals. So I decided to move the colonists to Mercury (another experiment ^^). But the Titan colony screen shows that this moon is still a detsination for colonists, thus civilian transports keep moving unfortunate peaple to Titan. Is there any way for me to set the status to "please dear colonists, go elsewhere if you don't mind because I will soon move the infrastrucure away and you will uncomfortably die" ?