Dyson sphere

A Dyson sphere is a hypothetical megastructure originally described by Freeman Dyson that would orbit a star to completely surround it, capturing all or most of its emitted energy. Dyson speculates that this structure would be a logical consequence of the survival and increasing energy demands of a technologically advanced civilization, and suggested that the search for evidence of such a structure could lead to the detection of extraterrestrial life with advanced intelligence.