What is "theia"

In Greek mythology, Theia (sometimes rendered Thea, Théa or Thia), also called Euryphaessa "wide-shining", is a Titaness. The name Theia alone means simply "goddess" or "divine"; Theia Euryphaessa brings overtones of extent (, eurys, "wide", root: ) and brightness (, phaos, "light", root: φαεσ-). Her brother/consort is Hyperion, a Titan and god of the sun, and together they are the parents of Helios (the Sun), Selene (the Moon), and Eos (the Dawn).

Theia was a Greek goddess, a Titan who gave birth to the Moon goddess, Selene.

Theia may also refer to:

• Theia (planet), a planet that may have been involved in the creation of the Moon
• Teia, last king of the Ostrogoths in Italy
• Telescope for Habitable Exoplanets and Interstellar/Intergalactic Astronomy, a proposed space telescope

Theia is a hypothesized ancient planetary-mass object in the early Solar System that, according to the giant impact hypothesis, collided with the early Earth around 4.31 billion years ago ( bya). According to the hypothesis, Theia was an Earth trojan about the size of Mars, with diameter of about . Geologist Edward Young of the University of California, Los Angeles, drawing on an analysis of rocks collected by Apollo missions 12, 15, and 17, suggests that Theia collided head-on with Earth, in contrast to the previous theory that suggested a glancing impact. Models of the impact propose that Theia's debris gathered around Earth to form the early Moon. Some scientists think that the material thrown into orbit originally formed two moons that later merged to form the single moon we know today. The Theia hypothesis also explains why Earth's core is larger than would be expected for a body its size: according to the hypothesis, Theia's core and mantle mixed with Earth's.

Theia (1973 – after 1989) was a French Thoroughbred racehorse and broodmare. She was widely regarded as the best European filly of her generation in 1975, when she was unbeaten in three races including the Prix du Calvados and the Criterium des Pouliches. In the following year she added wins in the Prix Vanteaux and Prix de la Nonette and finished second in a strongly-contested renewal of the Prix Saint-Alary, but appeared to be just below top class. She was later exported to race in the United States, where she campaigned with limited success. She was later a useful broodmare, producing several winners.