Tei Tenga

Tei Tenga is a fictional moon or planet where Doom was originally supposed to take place during its first and third episodes, according to Tom Hall's preliminary design document for the game.

The celestial body is tidally locked and thus the same&#160;hemisphere&#160;always faces the star it orbits;&#160;therefore it&#160;doesn't have day and night cycles. Because of the synchronous rotation, it is divided into two sections, a continually bright&#160;hemisphere called the Lightside, and a complementary sunless hemisphere called the Darkside.

Although it is initially referred to as the giant moon Tei Tenga, it is called a planet in a few other instances.

Tei Tenga does appear in the finished Doom games, although somewhat obscurely, being named in some of the computer console display textures. Additionally, some fan-made PWADs expand on the Tei Tenga concept.

The meaning may come from Chinese. In Spanish "Te tengo" means "I've got you".