About half of Americans believe that life exists somewhere else in the cosmos, according to a 2013 Huffington Post/YouGov poll. And a quarter of them think that extraterrestrials already have visited our planet [source: Swanson].
But so far, sweeps of the sky with Earth-based telescopes for signals that might be beacons from distant civilizations have proven fruitless, possibly because the Earth's atmosphere interferes with such messages reaching us. That's why searchers for extraterrestrial civilizations are eager for the deployment of more orbital observatories such as the James Webb Space Telescope. That satellite, which is expected to launch in 2018, will have the ability to search for the chemical signs of life in the atmospheres of distant planets outside our solar system [source: Kramer]. That's a start, but an even more aggressive space-based effort to look for clues of extraterrestrials might finally help us to answer the question of whether we have company out there.