Scientists say it could take least 1,500 years before humans make contact species aliens, or them to communicate with or find us. Astronomers Cornell University in the USA combined two existing theories the possibility of life existing other planets to form a new equation. One these theories is the Fermi Paradox described by physicist Enrico Fermi 1950. This states that while billions of Earth-like planets exist in our galaxy, not one has made contact Earth yet. The other is the mediocrity principle, which suggests that because there is life Earth, it will typically exist Earth-like planets the universe.
Study author Evan Solomonides will soon present a research paper his theory. He said: "We haven't heard from aliens yet, as space is a big place, but that doesn't mean no one is there." According Solomonides, extraterrestrials could have received signals Earth. However, he proposes that ET would not have been able to decipher them. He said they would need to decode the light waves sounds and analyse 3,000 human languages to understand any messages. He said that signals Earth have only reached 8,500 stars and that the Milky Way galaxy alone contains 200 billion stars. He added: "If we stop listening or looking, we may miss the signals, so we should keep looking."