The main sequence in stellar classification from hot to cold: O, B, A, F, G, K and M Extended types for late giant carbon-star classes are: R (or C-R), N or (C-N) and S Oh Be A Fine Girl/Guy, Kiss Me (Right Now — Smack):

The order of planets from the Sun: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune Mean Very Evil Men Just Shortened Up Nature Mary's "Virgin" Explanation Made Joseph Suspect Upstairs Neighbour

The Galilean moons are the four largest moons of Jupiter: Io, Europa, Ganymede and Callisto. They were discovered by Galileo Galilei around January 1610 and were the first group of objects found to orbit another planet. Their names derive from the lovers of Zeus. I Eat Green Cows I Enjoy Grated Cheese