About SETI
The Search for Extraterrestrial Intelligence: listening for signals from civilisations on other worlds.
- Also known as
- Search for Extraterrestrial Intelligence
- Began
- 1960 (Project Ozma)
- Method
- Radio and optical telescopes
- Famous candidate
- The Wow! signal (1977)
The full story, section by section
The story of SETI in 3 parts. Tap any part to read it in full.
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BeginningsIn 1959 physicists Giuseppe Cocconi and Philip Morrison suggested listening near the 1420 MHz radio line of hydrogen, a frequency any radio astronomer would know.Read this part → Illustration drawn for this site — not a photograph.
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SETI and UFOsMost SETI scientists are sceptical of UFO reports.Read this part → Illustration drawn for this site — not a photograph.
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The silenceAfter more than sixty years without a confirmed signal, scientists still debate what the silence means.Read this part → Illustration drawn for this site — not a photograph.
Key people
The people at the centre of the story — witnesses, investigators, officials and sceptics:
- Carl SaganCarl Edward Sagan was an American astronomer, planetary scientist, and science communicator who lived from 1934 to 1996. He played a major role in space missions, discovered Venus's high surface temp…
- Avi LoebAbraham Avi Loeb is an Israeli-American theoretical physicist and professor at Harvard University who has researched astrophysics and cosmology. He became widely known for arguing that interstellar o…
Related cases & events
Events and sightings linked to SETI:
🗓️ Event · 2 min readWow! signalA strong radio signal recorded in 1977 that looked like what SETI was searching for, and was never heard again.
🗓️ Event · 2 min readʻOumuamuaThe first object known to have come from outside the Solar System, found in 2017 — and briefly suggested to be an alien probe.
🗓️ Event · 2 min read3I/ATLASThe third known interstellar object, a comet found in July 2025 that sparked claims of alien technology.Programs, organizations & documents
The official programs, groups and papers involved:
Related topics & places
Ideas, terms and places that come up in the story:
📖 Term · 5 min readDrake equationThe Drake equation is a probabilistic argument written by radio astronomer Frank Drake in 1961 to estimate the number of active, communicative extraterrestrial civilizations in the Milky Way. Because several of its terms rely on pure conjecture, the formula c…
📖 Term · 5 min readFermi paradoxThe Fermi paradox is the contradiction between the high probability that extraterrestrial civilizations exist and the lack of any clear evidence for them. The term originated from a 1950 lunchtime conversation in Los Alamos involving physicist Enrico Fermi, w…
🧭 Topic overview · 2 min readAre aliens real?What science and the official investigations say about whether extraterrestrial life exists and whether it has visited Earth.🗓️ SETI on the UAP timeline
- Greer's CSETI allegedly briefs Congress with a list of sites tied to UAP. Read the article →
- CSETI says a covert group using unacknowledged programs manages the UAP issue. Read the article →
- CSETI briefs members of Congress that a covert group controls parts of the UAP issue. Read the article →
- CSETI allegedly briefs Obama officials and senators on breakthrough energy. Read the article →
🛸 UFO sightings about SETI
Sightings that mention SETI
More in the encyclopedia
Other articles that link to or mention SETI:
- 1978 House SETI hearingThe 1978 House SETI hearing took place on September 19 and 20, 1978, at the Rayburn House Office Building in Washington, D.C., and was chaired by Representative Don Fuqua.
- Project GrudgeProject Grudge was the United States Air Force's UFO investigation program that ran from February 1949 to March 1952. The study operated primarily to explain sightings away, ease public anxiety, and …
- Project Preserve DestinyProject Preserve Destiny is an alleged secret United States program in which genetically engineered humans reportedly communicated telepathically with extraterrestrials known as Greys. According to f…
- Projects Sign, Grudge and Blue BookProjects Sign, Grudge, and Blue Book were three successive United States Air Force investigations of unidentified flying objects based at Wright-Patterson Air Force Base in Ohio from 1948 until the e…
- Project Blue BookProject Blue Book was the United States Air Force's official study of unidentified flying objects based at Wright-Patterson Air Force Base in Ohio from March 1952 until December 1969. The project col…
- Project PegasusProject Pegasus is an alleged secret United States government programme from the late 1960s onward involving children in time travel and teleportation experiments. According to lawyer Andrew Basiago,…
- Operation PratoOperation Prato was a Brazilian Air Force investigation conducted in late 1977 around Colares island in Pará, Brazil, regarding local reports of strange, light-emitting phenomena that allegedly attac…
- Project MogulProject Mogul was a top-secret US Army Air Forces project conducted from 1947 to early 1949 that used high-altitude balloons and microphones to listen for Soviet atomic bomb tests. Although the ballo…
- Project AquariusProject Aquarius is the name of an alleged top-secret United States government UFO program that is widely considered a fake and is closely tied to the Majestic 12 story and a disinformation campaign …
- Project TwinkleProject Twinkle was a United States Air Force effort to photograph and measure green fireballs and unusual lights reported over New Mexico from late 1948 onward. The project operated camera stations …
- Breakthrough Propulsion PhysicsThe Breakthrough Propulsion Physics Project was a small NASA research project that ran from 1996 to 2002. It studied advanced spacecraft propulsion ideas requiring new discoveries in physics, such as…
- Project StorkProject Stork was a 1953–1955 contract program between the Battelle Memorial Institute and the United States Air Force to scientifically study UFO sighting reports. The work involved creating standar…
- Strategic Defense InitiativeThe Strategic Defense Initiative, nicknamed "Star Wars", was a proposed United States system announced by President Ronald Reagan in March 1983 to defend against ballistic nuclear missiles. The progr…
- Project MagnetProject Magnet was a small Canadian government study on unidentified flying objects established by the Department of Transport in December 1950 and directed by Wilbert Brockhouse Smith. The project a…
- MKULTRAMKUltra was an illegal human-experimentation program run by the Central Intelligence Agency from 1953 to 1972 to find procedures and drugs to alter human behavior for mind control and interrogation. …
- Secrecy & cover-up (topic)This overview page covers official secrecy, classification, and cover-up claims regarding unidentified anomalous phenomena from 1947 to 2023. It outlines historical classified studies, released gover…
- Government programs (topic)This encyclopedia overview outlines government and private programs established to study UFOs and UAPs from 1947 to 2023. U.S.
- Beings & bodies (topic)This topic overview covers reports and claims about non-human beings, bodies, and biological material spanning from 1947 to 2023. It outlines various second-hand and anonymous accounts involving cras…
Questions & answers
What is SETI?
SETI: The Search for Extraterrestrial Intelligence: listening for signals from civilisations on other worlds. Read: SETI →
What else is SETI called?
SETI is also known as Search for Extraterrestrial Intelligence.
Who is Carl Sagan?
Carl Sagan: Carl Edward Sagan was an American astronomer, planetary scientist, and science communicator who lived from 1934 to 1996. He played a major role in space missions, discovered Venus's high surface temperature, co-created interstellar messages, and co-wrote and presented the popular television series Cosmos. He also worked extensively to study UFO reports scientifically while remaining a prominent skeptic of the extraterrestrial hypothesis. Read: Carl Sagan →
Who is Avi Loeb?
Avi Loeb: Abraham Avi Loeb is an Israeli-American theoretical physicist and professor at Harvard University who has researched astrophysics and cosmology. He became widely known for arguing that interstellar objects passing through the Solar System, such as ʻOumuamua, could be alien technology. His claims have been widely rejected by other scientists and led to professional isolation, though he founded the Galileo Project and was named chair of the UAP Science Advisory Council in June 2026. Read: Avi Loeb →
What was Wow! signal?
Wow! signal: A strong radio signal recorded in 1977 that looked like what SETI was searching for, and was never heard again. Read: Wow! signal →
What was ʻOumuamua?
ʻOumuamua: The first object known to have come from outside the Solar System, found in 2017 — and briefly suggested to be an alien probe. Read: ʻOumuamua →
What is Galileo Project?
Galileo Project: The Galileo Project is a privately funded research project founded in July 2021 and led by Harvard astrophysicist Avi Loeb to search for physical evidence of extraterrestrial technology. By late 2025, the project operated sky-watching observatories in Cambridge, Massachusetts, Pennsylvania, and Las Vegas to photograph unidentified aerial phenomena, study interstellar objects, and search for alien satellites. The project has drawn strong criticism and mixed reactions from other scientists regarding its methods, claims, and findings. Read: Galileo Project →
What is Drake equation?
Drake equation: The Drake equation is a probabilistic argument written by radio astronomer Frank Drake in 1961 to estimate the number of active, communicative extraterrestrial civilizations in the Milky Way. Because several of its terms rely on pure conjecture, the formula cannot support firm conclusions and yields results ranging from less than one civilization to tens of millions. Its primary value is setting out what scientists need to know and serving as an agenda for discussion. Read: Drake equation →
What is Fermi paradox?
Fermi paradox: The Fermi paradox is the contradiction between the high probability that extraterrestrial civilizations exist and the lack of any clear evidence for them. The term originated from a 1950 lunchtime conversation in Los Alamos involving physicist Enrico Fermi, who asked "Where is everybody?" Proposed explanations range from life being extremely rare and civilizations dying out quickly to aliens choosing to stay hidden, while decades of searches have found no clear signs of extraterrestrial life. Read: Fermi paradox →