Sixty years ago, famed physicist Freeman Dyson theorized that advanced civilizations, in their ongoing quest to find more living space and energy, would convert their solar system into a megastructure enclosing their star. This gave rise to the concept of megastructures, many of which have been theorized over the years. These hypothetical structures are one of many technosignatures SETI researchers are on the lookout for as they probe the stars for signs of intelligent life.