Image: Depiction of a ringworld. Credit: Hill/Wikimedia Commons
In the search for intelligent extraterrestrials, scientists listen for incoming radio signals and they hunt for Earth-like planets. Some scientists are also looking for megastructures constructed by aliens.
NASA’s Kepler space telescope searches for planets using the transit method–Kepler’s sensors detect dips in brightness caused when an alien planet passes in front of its star from Kepler’s perspective. And this same method is used by scientists searching the universe for alien megastructures.
According to Universe Today, astronomer Geoff Marcy, who was recently appointed to the new Watson and Marilyn Alberts Chair for SETI (Search for Extraterrestrial Intelligence) at the University of California at Berkeley, was awarded a grant to hunt for evidence of Dyson spheres using Kepler data. A Dyson sphere is a theoretical megastructure envisioned by theoretical physicist Freeman Dyson consisting of a giant array of solar panels that would surround a star to harvest its energy.
Scientists hunting alien megastructures are also looking for theoretical structures known as ringworlds. Universe Today explains that ringworlds “would consist of a giant ring in orbit around a star, constructed comfortably inside the star’s habitable zone.”
Whether alien megastructures actually exist is unknown. But as Universe Today points out, “The possibility alone is exciting enough to make it worth continuing to look.”