Aether (᾿Αιθήρ) is the ancient-Greek god of the high atmosphere, containing the air breathed by the gods, in contrast to the ordinary, lower level air breathed by the mortals. Aether is the light and his sister and wife Hemera is the day. Above Aether is the heavenly sphere of Ouranos. Aether is one of the Protogenoi the first-born gods representing the five Greek elements (Earth, Fire, Water, Lower Air, and Upper Air).
According to Hesiod, Aether was the son of Erebus (darkness) and Nyx (night). Aether and Hemera had the following children: