Andromeda galaxy - The nearest spiral galaxy like our own.
asteroid belt - The group of asteroids orbiting between Mars and Jupiter.
Callisto was a constant companion to Diana (Artemis) the archer. Jupiter spotted Callisto and once again fell in love. This time, to disguise himself, he changed his form to resemble Diana. Callisto later bore him a son named Arcas. When Juno found out about the affair, she punished Callisto by changing her into a bear. One day, when Arcas was hunting in the forest, he spotted Callisto, who rushed forward to greet him. Arcas, thinking the bear was charging him, aimed his arrow at Callisto. Jupiter immediately placed them both in the sky, where they are now known as Ursa Major and Ursa Minor, the Great Bear and Little Bear.
comet - An icy interplanetary object that, when heated by the sun, releases gases that form a bright head and diffuse tail.
constellation - One of 88 imaginary patterns found among the stars, some of which resemble figures from ancient mythology or legend.
diameter - The width of an object, like a star.
Earth (Gaia) was the mother and wife of Uranus and the mother of Saturn.
eclipse - An event in which the shadow of one body falls on another body.
ecliptic - The plane of Earths orbit and that of the rest of the solar system; the path of the sun (and, roughly, the planets) across the sky.
Europa was a lovely young Phoenician princess. Jupiter was taken with her too, so he turned himself into a white bull and visited her as she strolled with her maidens on the seashore. The bull convinced Europa to ride on his back and carried her off into the sea. Jupiters affair with Europa went unnoticed by Juno, so Europa was never punished.
galaxy - A grouping of billions of stars that may have a spiral, barred, spherical, or irregular shape.
Ganymede was a boy kidnapped by Jupiter from the island of Crete, who served as cupbearer to the gods at Olympus.
Io was a beautiful nymph to whom Jupiter was attracted. To conceal his affair from his wife, Jupiter covered the Earth in clouds. Juno caught on and started to part the clouds to see what Jupiter was up to, but he quickly transformed Io into a cow. Juno wasnt fooled, however, and she tormented Io the cow and caused her to wander the Earth. Eventually, Juno transformed Io back into a woman after Jupiter promised not to make any more advances.
Jupiter (Jove) (Zeus) was the son of Saturn and brother of Poseidon and Hades. As a deity, his duties included controlling rain and ruling the sky. Although Juno (Hera) was his official wife, his affairs were numerous, and he often changed himself into another creature to woo mortal women.
light-year - The distance light travels in one year, about 6 trillion miles.
Luna (Diana) or Artemis the archer was the goddess of the moon. Her bow can be seen as the crescent moon. Some Native American tribes see the form of a rabbit in the moon.
Mars (Ares) was the god of war, thought to embody the essence of brutality and devastation. He had four children with Aphrodite: Eros, Deimos (panic), Phobus (fear), and Harmonia.
Mercury (Hermes) was the messenger god. He carried a staff called the caduceus. As a baby, he made the first lyre and stole cattle from his half-brother Apollo. Later, Hermes and Apollo were reconciled and Hermes gave him the lyre he had made.
meteor - A rapidly moving luminous object visible for a few seconds in the sky; usually a rock the size of a pebble or smaller.
meteor shower - The passage of a concentrated group of meteors that seems to originate from one location, occurring when Earth passes through comet debris.
nebula - A cloud of dense gas and/or dust in deep space or surrounding a star.
north celestial pole - The point in space directly overhead for an observer at the North Pole; currently nearest the star Polaris, the North Star.
satellite - Any object orbiting a larger body.
Saturn (Cronus) was the father of Jupiter and son of Uranus and Gaia. He was married to his sister Rhea, and their children included Hestia, Hades, Poseidon, Demeter, Hera and Zeus.
spectral class - A class to which a star belongs based on its spectrum, which is determined by its temperature. The spectral classes are: O, B, A, F, G, K, and M, from hottest to coolest.
Titan. The children of Uranus and Gaia were called Titans. Their names were Oceanus, Coeus, Crius, Hyperion, Iapetus, Theia, Rhea, Themis, Mnemosyne, Phoebe, Tethys, and Cronus.
Venus (Aphrodite) was the goddess of love, beauty, and marriage. She was married to Hephaestus, but she had numerous affairs, including one with Mars. Native Americans of Central America saw Venus as the feathered serpent Quetzalcoatl. The reappearance of Venus after a long period of absence signified the return of this god to the Aztecs.
zenith - The point directly overhead.