A Dyson Sphere is a hypothetical megastructure composed of a massive sphere that surrounds a star, collecting as much of it's energy as possible. Dyson spheres are named for Freeman Dyson, who first proposed these structures.
Dyson Spheres in Science Fiction
- In the Star Trek Universe, a Dyson Sphere made by an unknown alien civilization was seen in TNG "Relics".
- In the Warhammer 40,000 universe, an ancient Dyson Sphere exists that the Tyranid hive fleet Leviathan has avoided. This is believed to be a C'tan construct.
- In Mass Effect, the Geth are building a Dyson Sphere.