Are Alien Probes Hiding in Our Backyard? A New Study Says We’ve Barely Looked

Even at this early stage in our space faring age, humanity has already begun sending probes that will eventually reach other solar systems, even if that was not their original intention. Five robotic explorers - Pioneer 10 and 11, Voyager 1 and 2, and New Horizons - are all on escape velocities out of the solar system, and might someday enter another one. They will no longer be operational at that point, but they serve as a proof of concept that spacefaring civilizations do indeed build interstellar probes. Which raises the obvious question - has anyone else sent their own robotic explorers to ours? In a recent paper, published in the Proceedings of the IAU Centenary Symposium, astronomer T. Joseph W. Lazio, points out a painful truth - we still have no idea, and our technology will need to get much better if we plan to find out.