From Markus Hammonds at io9: “The Hunt for Alien Megastructures”. Turns out that people are already using observational data to try to identify planet-scale structures that may exist in other solar systems:
To find a Dyson sphere, you need to look for a specific signature of infrared light, emitted at just the right set of wavelengths.
And thats just what an ongoing project, headed by Dick Carrigan at Fermilab, has been doing. Astronomers regularly survey the sky to see what they might find, and Carrigan has been hunting through infrared data to search for Dyson spheres. To date, the project has a handful of candidates, but nothing definitive. Not yet.
It’s interesting that there’s a certain foundation of science fiction concepts that were established in the early days of the Space Age, when mainstream scientists and writers shared much more: Dyson’s paper describing the infrared discovery of artificial megastructures was published in Science, after all