A is for the Andromeda galaxy. Home of the multi-tentacled Kelvans.
B is for Beta Stromgren.
C is for the Canopus Planet.
D is for Double red alert!
E is for Earth. Minor blue-green world that is blasting the rest of the galaxy with it's EM radiation signals that are mostly gibberish.
F is for Fat Federation Captains.
G is for the Gorn Hegemony.