It could be 1,500 years before billion billions contact extraterrestrials galaxy humans languages life one other place possibility should signals space stars theories there yet make billion billions contact extraterrestrials galaxy humans languages life one other place possibility should signals space stars theories there yet with aliens. Astronomers joined two billion billions contact extraterrestrials galaxy humans languages life one other place possibility should signals space stars theories there yet about the billion billions contact extraterrestrials galaxy humans languages life one other place possibility should signals space stars theories there yet of life on billion billions contact extraterrestrials galaxy humans languages life one other place possibility should signals space stars theories there yet planets. One theory is the Fermi Paradox. This states that while billion billions contact extraterrestrials galaxy humans languages life one other place possibility should signals space stars theories there yet of Earth-like planets exist in our billion billions contact extraterrestrials galaxy humans languages life one other place possibility should signals space stars theories there yet , not billion billions contact extraterrestrials galaxy humans languages life one other place possibility should signals space stars theories there yet has made contact billion billions contact extraterrestrials galaxy humans languages life one other place possibility should signals space stars theories there yet . The other is the mediocrity principle. This suggests that because there is billion billions contact extraterrestrials galaxy humans languages life one other place possibility should signals space stars theories there yet on Earth, it will exist on Earth-like planets in the universe. Researcher Evan Solomonides said: "We haven't heard from aliens yet, as billion billions contact extraterrestrials galaxy humans languages life one other place possibility should signals space stars theories there yet is a big billion billions contact extraterrestrials galaxy humans languages life one other place possibility should signals space stars theories there yet , but that doesn't mean no one is out billion billions contact extraterrestrials galaxy humans languages life one other place possibility should signals space stars theories there yet ." He said billion billions contact extraterrestrials galaxy humans languages life one other place possibility should signals space stars theories there yet may not have decoded the billion billions contact extraterrestrials galaxy humans languages life one other place possibility should signals space stars theories there yet we sent. They would also need to decode 3,000 human billion billions contact extraterrestrials galaxy humans languages life one other place possibility should signals space stars theories there yet . Signals from Earth have reached 8,500 billion billions contact extraterrestrials galaxy humans languages life one other place possibility should signals space stars theories there yet ; our Milky Way billion billions contact extraterrestrials galaxy humans languages life one other place possibility should signals space stars theories there yet has 200 billion billions contact extraterrestrials galaxy humans languages life one other place possibility should signals space stars theories there yet stars. Solomonides said: "If we stop listening or looking, we may miss the signals, so we billion billions contact extraterrestrials galaxy humans languages life one other place possibility should signals space stars theories there yet keep looking."