We're not alone in the universe -- or so say half of Americans in a new HuffPost/YouGov poll. And a quarter of Americans think that alien visitors have come to Earth.
According to the new survey, 50 percent of Americans think that there is some form of life on other planets, while only 17 percent think that there's not. Another 33 percent said they aren't sure.
Respondents were somewhat more skeptical when asked whether there's intelligent life on other planets. Thirty-eight percent said there is, 21 percent said there's not, and the percentage saying they're not sure edged up to 42 percent.
Scientists with the SETI institute have been using microwave radio to attempt to detect communication from other solar systems since the 1960s. And NASA programs, including the James Webb Space Telescope, set to launch in 2018, are currently underway to help identify other planets in the universe that may support life.
In the HuffPost/YouGov poll, a quarter of Americans said that they think aliens have visited Earth, while a third said they have not -- the rest of the respondents weren't sure. Among those who said that life exists on other planets, 45 percent said that aliens have visited Earth.
Many people believe our best chance of communicating with extraterrestrial life will be via radio signals. In 1977, researchers detected a signal that some claimed bore the marks of extraterrestrial origin -- hence the "Wow!" written in the margin.
Physicist Stephen Hawking has argued that intelligent life on other planets is likely to exist, but that if aliens had visited Earth it would have been a "much more unpleasant" experience than any UFO sightings.
College graduates in the survey were somewhat more likely than non-college graduates to believe that life exists in some form elsewhere in the universe, but no more likely to say that aliens have visited Earth.
And older respondents were more likely than younger ones to say that Earth has experienced alien visitors.
The HuffPost/YouGov poll was conducted June 11-12 among 1,000 adults using a sample selected from YouGov's opt-in online panel to match the demographics and other characteristics of the adult U.S. population. Factors considered include age, race, gender, education, employment, income, marital status, number of children, voter registration, time and location of Internet access, interest in politics, religion and church attendance.
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This is the Pioneer Plaque, one of two cosmic dog-tags attached to the Pioneer 10 and 11 spacecraft, the first human-made matter to leave the solar system. Carl Sagan and his wife Linda, along with astronomer Frank Drake, designed the plaque. It contains a map of the solar system with the path of the spacecraft, as well as images of a man and a woman, which were criticized for their nudity when the plaques were created.
The Golden Records, sent out with the Voyager I and II spacecraft, contain diagrams representing basic scientific concepts, but may be most notable for their inclusion of music, ranging from Chinese musician Guan Pinghu to early rocker Chuck Berry. The records will remain on the interstellar probes for their multi-millennial mission, passing relatively close to a star in about 40,000 years. If extraterrestrials can manage find these needles in the galactic haystack, they'd almost certainly be advanced enough to find us.
The Arecibo message, which was broadcast as a radio signal in 1974, contains a representation of the numbers 1-10, as well as various information about the chemicals that make up life on this planet. At the bottom, there's even a diagram of the picturesque Arecibo telescope. Frank Drake and Carl Sagan also contributed to the design, which is depicted here in color to remove ambiguity from the different parts of the message. We definitely can't expect a reply to this one; it will take 25,000 years to reach its target and another 25,000 before we'd receive any response. Donald Campbell, professor of astronomy at Cornell University later <a href="http://web.archive.org/web/20080802005337/http://www.news.cornell.edu/releases/Nov99/Arecibo.message.ws.html" target="_hplink">confirmed this</a>, saying, "It was strictly a symbolic event, to show that we could do it."
The first Cosmic Call message, sent out from a radio telescope in Ukraine, included a signal with this information. It's a sort of numerical dictionary, which matches up binary representations of numbers with the symbols that will be used to represent them in the rest of the message. Subsequent parts of the message go on to define mathematical operations and fundamental scientific facts. <a href="https://docs.google.com/viewer?a=v&q=cache:54E2DsuQ1JIJ:www.astrosurf.com/luxorion/Documents/seti-dutil-dumas.pdf+&hl=en&gl=us&pid=bl&srcid=ADGEESiKrcWWCBuKAIg6lQyKOUySNwqyHXRgmd9RcF6nWq5U6Ji3qZ4RJXzC55NvR19JhUV9I3oeoyI29jMAwXWc8-mOuJSG8bBTzxWCUvxWl-FxwMa2EREg5uDxFYpeggirJ0VWvKpU&sig=AHIEtbSFFlViE_wfSo8H2LXQFyLJq5lCCQ" target="_hplink">A detailed explanation can be found here</a>. <a href="http://www.matessa.org/~mike/dd-pr.html" target="_hplink">Canadian physicists Yvan Dutil and Stephane Dumas led the efforts</a> to send the Cosmic Call, which was sent alongside a transmission of the Arecibo message. Image courtesy Yvan Dutil and Stephane Dumas.
The Teen-Age Message, composed in part by teens from across Russia, was broadcast in August and September 2001. In addition to bilingual greetings in Russian and English, the broadcast includes the "1st Theremin Concert for Aliens," a series of famous melodies played on the <a href="http://www.youtube.com/watch?v=cd4jvtAr8JM" target="_hplink">electronic instrument</a>. The image above contains several glyphs representing various aspects of humanity and life on planet earth. Image: Alexander Zaitsev
In 2008, <a href="http://www.nasa.gov/topics/universe/features/across_universe.html" target="_hplink">NASA transmitted</a> the Beatles' 'Across The Universe' in the direction of the North Star, Polaris, located 431 light years away. The transmission was sent from a station outside Madrid that's part of NASA's international antenna array known as the Deep Space Network. It celebrated the 40th anniversary of the song's recording and the 50th anniversary of NASA's founding. When NASA notified Paul McCartney, the former Beatle told the Administration to "Send my love to the aliens."