10-23-2015, 03:31 PM
One possibility that has crossed my mind is a naturally evolved Dyson swarm. We have naturally evolved photosynthetic swarms on Earth - the phytoplankton in the sea form a swarm of sorts, as do the land plants and forests. If a system has enough material in orbit to support a photosynthetic swarm, then it could evolve into a self-regulating macroscopic structure that would be detectable with relatively primitive instruments. The most fertile location for a swarm of this kind could be a protoplanetary disk or relatively young system full of dust and comets.