The Search for Extraterrestrial Megastructures Gains Momentum
Most people are aware of the various attempts being made to search for alien life in our galaxy and beyond, including SETI’s (Search for Extraterrestrial Intelligence) efforts to detect radio transmissions and Kepler’s search for habitable planets. But few are aware of another serious attempt being made to track down civilizations more advanced than our own – the search for extraterrestrial megastructures.
Megastructures are vast structures constructed on an astronomical scale which, until now, have mostly been reserved for the realm of science fiction such as the Star War’s ‘Death Star’ or the Halo video game’s ‘ring world’. However, the possibility of astroengineered artifacts existing around other stars is now being taken more seriously with some scientists hypothesizing that any civilization that is millions or even billions of years older than our own could well have constructed such megastructures either as a way to harness energy or as place for habitation.
In 1960, Freeman Dyson published a paper entitled Search for Artificial Stellar Sources of Infrared Radiation. His suggestion was that any megastructure constructed around a star should show itself by emitting more infrared light than it should. The solution was simple – look for any sources of infrared which appeared artificial.
Unfortunately, this isn’t as simple as it sounds because many stars are surrounded by dust which emits substantial infrared rays. Therefore, locating a megastructure would involve searching for a specific signature of infrared light, emitted at just the right set of wavelengths, a mammoth task that is currently being undertaken in an ongoing project by Dick Carrigan at Fermilab.
But infrared isn’t the only way to spot Dyson spheres. In principle, any large artificial objects in orbit around other stars should be detectable in exactly the same way exoplanets are. In 2012 Geoff Marcy, an exoplanet researcher, was given a grant to hunt for evidence of Dyson spheres in data recorded by Kepler.
Although nothing definitive has been found yet, the possibility of discovering astroengineered megastructures is exciting enough to make it worth continuing to look.