The Search for Alien Artifacts Is Coming Into Focus

From surveys of the pre-Sputnik skies to analysis of interstellar visitors, scientists are rethinking how and where to look for physical traces of alien technology. Science fiction is awash in the material remnants of extraterrestrial civilizations, which surface in everything from the classic books of Arthur C. Clarke to game franchises like and . The discovery of the first interstellar objects in the solar system within the past decade has sparked speculation that they could be alien artifacts or spaceships, though the scientific consensus remains that all three of these visitors have natural explanations. That said, scientists have been anticipating the possibility of encountering alien artifacts since the dawn of the space age. "In the history of technosignatures, the possibility that there could be artifacts in the solar system has been around for a long time," says Adam Frank, a professor of astrophysics at the University of Rochester.