A Dyson Sphere is a hypothetical megastructure that completely encompasses a star and hence captures most or all of its power output. It was first described by Freeman Dyson. Dyson speculated that such structures would be the logical consequence of the long-term survival and escalating energy needs of a technological civilization, and proposed that searching for evidence of the existence of such structures might lead to the detection of advanced intelligent extraterrestrial life.
Although such megastructures may be theoretically possible, all plans to build a fixed-in-place Dyson sphere are currently far beyond humanity’s engineering capacity. However, parts of the technology, like orbiting satellites and solar sails, have already been developed, but the number of craft required to obtain, transmit, and maintain a complete Dyson sphere far exceeds the present-day industrial capabilities.