A paper recently accepted for publication in Acta Astronautica proposes that, rather than use radio dishes to listen for possible signals from extraterrestrial civilizations, scientists and engineers begin work on a network of probes that could replicate themselves as they travel from one star system to another. Each probe would land on a planet and mine its materials to create a copy of itself, which would then launch itself into space and continue the journey. Furthermore, the probes could communicate with each other and with Earth by harnessing the power of stars to bend and amplify light. Paper author and University of Liege astrophysics professor Michael Gillon says, “[T]he Sun (and any other star) is an antenna much more powerful than we could ever build.”
What’s the Big Idea?
Gillon’s paper is based on one hypothesis used to explain the Fermi Paradox, which notes the contradiction between the high probability of extraterrestrial civilizations and the lack of contact with those civilizations. That hypothesis suggests that as-yet-undetected self-replicating probes are exploring or have already explored this galaxy, including our solar system. Gillon says, “We are still far from being able to build an actual self-replicating interstellar spaceship, but only because our technology is not mature enough, and not because of an obvious physical limitation.”