Callisto, Titan, Deimos and Phobos are actually satellites, not planets. Rename them to something cooler and more available, like stars:
- Sirius (the brighest)
- VY Canis Majoris (the largest star known)
- Antares
- Betelgeuse
- Rigel
- Denebola
- Proxima Centauri (the nearest one besides the Sun)
- Sun (sounds cool)
- Etc...
Or universe-related generic names, like Nova, Supernova, Black Hole, Star, Galaxy, Quasar...
EDIT: other than that, good luck with your servers, and keep up the space-themed thing!
- Sirius (the brighest)
- VY Canis Majoris (the largest star known)
- Antares
- Betelgeuse
- Rigel
- Denebola
- Proxima Centauri (the nearest one besides the Sun)
- Sun (sounds cool)
- Etc...
Or universe-related generic names, like Nova, Supernova, Black Hole, Star, Galaxy, Quasar...
EDIT: other than that, good luck with your servers, and keep up the space-themed thing!