The Search for Extra-Terrestrial Intelligence (SETI) is an international effort devoted to answering one of humanity’s most perplexing questions: are we alone in the universe? The tumultuous history of this ambitious endeavor rose from humble beginnings at the dawn of radio in the early 1900s. Nikola Tesla suggested in 1896 to create an extreme version of a wireless electrical transmission system to contact a civilization thought to exist on Mars, which he tested with lackluster results. Between August 21-23 in 1924, when Mars appeared the closest to Earth during its 80 year opposition cycle, the United States promoted a “National Day of Silence” for a 36 hour period, where all radios went quiet for five minutes at the end of every hour, while the United States Naval Observatory tuned in to detect any possible Martian messages, with US Army cryptographers eagerly awaiting any Martian rabble, though they only met with silence.
Fast forwarding to March 1955, American physicist John D. Kraus proposed a concept to scan space for incoming radio signals, leading to the construction of a flat-plane radio telescope at the Ohio State University. The telescope was dubbed “Big Ear,” and would become the center piece of the world’s first SETI program. In 1959, Philip Morrison and Giuseppe Cocconi proposed using the microwave spectrum while tuning into certain frequencies, such as the frequency of hydrogen (1,420Mhz), the most common element found in the universe. This created a chain reaction in the development of technology that lead to some rather interesting discoveries.
1960 found Cornell University astronomer Frank Drake performing Project Ozma which became the first modern SETI experiment, surveying a pocket of space with a radio telescope tuning in at the 1.42 gigahertz frequency toward sun-like stars. The reasonable idea only produced a single false signal originating from a high flying aircraft.
Soviet Scientists became strongly fascinated in SETI in the 1960s, performing searches with omni-directional antennas. Soviet astronomer Iosif Shklovsky wrote his groundbreaking book in 1962, Universe, Life, Intelligence, expanding on many of American space legend Carl Sagan’s ideas and leading both men to collaborate and coauthor a revision published in 1966, sowing the seeds needed to foster a relationship of cooperation in space between rival superpowers.
In 1977, while performing volunteer research at Ohio’s Big Ear, Jerry Ehman discovered the Wow! Signal, the first and only potential candidate for a radio signal emitted from an artificial extraterrestrial source, capturing the curiosity and enthusiasm of the entire world. Alas, it remains the only signal of its kind.
SETI continued growing steadily, becoming an international effort. In 1980, Carl Sagan, Louis Friedman, and Bruce Murray founded the Planetary Society, an organization dedicated to space exploration, planetary defense from near-earth objects, and the search for extraterrestrial intelligence, which has since gained near 60,000 members from over 100 nations.
Programs such as Sentinel, META, and BETA continued to build upon the innovations of the past, utilizing technology like spectrum analyzers and digital signal processing to search for SETI transmissions. As the price tags for these ambitious endeavors increased, many programs found themselves in the battlegrounds of Congress, some becoming ridiculed and canceled as was the case with NASA’s Microwave Observing Program (MOP), a long term effort conducting a sky survey targeting specific stars with the support of NASA’s Deep Space Network. MOP continued operations despite the lack of government funding, and in 1995 the SETI Institute revived the program, aptly renaming it Project Phoenix, backed by private benefactors. Phoenix searched for signals in a uniquely broad range of 1 Hz to 3,000 MHz. In 2004, the project announced that after a deep analysis of 800 stars within 200 light-years from Earth concluded that our planet resides in a quiet neighborhood, and Project Phoenix went offline.
Arecibo Observatory Radio Telescope in Puerto Rico, home of Project Phoenix from August 1998 onward.
There remain several facilities performing ongoing SETI radio searches, including the Low Frequency Array (LOFAR), the Murchison Widefield Array (MWA), and the Allen Telescope Array. In recent years, late legendary cosmologist Stephen Hawking collaborated with Russian billionaire Yuri Milner in 2015 to create the Breakthrough Initiatives, an exceptionally funded project that aims to advance the search for extra terrestrial intelligence, even offering competitions with sizable prize pools to those eager innovators of tomorrow. Other projects, like SETI@home, offer any passionate human the opportunity to volunteer their background computer power to perform analyses on SETI signal data, joining a netwrok of over 180,000 active participants utilizing over 300,000 computers! Interested in assisting humanity in the hunt for advanced extraterrestrial civilizations? Then look no further!
The SETI Institute, founded in 1984 by Thomas Pierson, provides public outreach and education in this curious field. Their mission statement aims “to explore, understand, and explain the origin and nature of life itself in the scope of the universe and the evolution of intelligence,” and they remain the gateway for aspiring intergalactic envoys and individuals hoping to contribute to mankind’s greatest quest.
The search for extraterrestrial intelligence has become a defining characteristic of our species, an embodiment of our tireless curiosity and desire to explore the unknown. As ventures into the realm of space exploration rapidly expand, some of our civilization’s most demanding questions might be at the precipice of resolving, though as is the case with any scientific endeavor, the answer to one great question might just lead to many deeper mysteries.
To be continued. (Dun dun dun)