Active SETI Highlights: Attempts To Communicate With Intelligent Extraterrestrials (PHOTOS)
The Search for Extraterrestrial Intelligence (SETI) is usually about collecting data. Researchers look at broad ranges of the electromagnetic spectrum for evidence of intelligent life, in hopes that an alien civilization has thought to send an interstellar signal our way. But in a few cases, humans have turned the tables, sending out messages from Earth in hopes of catching aliens' attention. This is Active SETI.
In the slideshow below, we've compiled a few well known attempts at Active SETI. While the efforts have been largely symbolic, the messages themselves and the logic behind them can be fascinating. Many people have heard of the Pioneer Plaque, with its images of a nude man and woman, but what about the time when NASA beamed the Beatles' classic 'Across The Universe' into space, or the broadcast that included data on humanity's latest mathematical achievements?
In the wake of NASA's observation that the planet Kepler-22b may support life as we know it, SETI researchers have begun direct their attention toward 'Earth's Twin.' It may only be a matter of time before Active SETI proponents begin sending messages on behalf of the human race.
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."