Selene

Selene was the goddess of the moon (not the only one, of course). She was the daughter of Hyperion and Theia (or of Pallas or Helios and Euryphaessa).

Her name undoubtedly comes from selas, 'bright light', 'brightness', to which word are also related hele, 'light of the sun' (compare Helios) and German hell, 'bright'. (For alternation between 'h' and 's' see Salmoneus.) The Roman equivalent goddess was Luna, whose name means 'moon' just as selene means 'moon' in Greek.