The United States is building a neutrino detector called IceCube in Antarctica (seen above) to detect naturally occurring neutrinos for scientific research. If they were to detect neutrinos at 6.3 petaelectron-volts (PeV) it could be a tell-tale sign of an artificially constructed signal, since there is no known natural process that would create neutrinos of that energy level. Researchers on earth however have identified two ways that such neutrinos could be created in the lab. Maybe we will soon be smart enough to be able to hear from more advanced civilizations.