I had known about some of these, and I had thought that some others are at least possible. I know that there is a ICAO code on Mars (since I had read about it

I had known about some of these, and I had thought that some others are at least possible. I know that there is a ICAO code on Mars (since I had read about it before). I think there are some airports that have a ICAO code but not IATA code and vice-versa, and some have a "pseudo-ICAO" code with letters and numbers together.