Hearing the Message

Poem by Peter Jekel

Maybe the aliens are looking for the civilizations that don’t send out SETI signals. - J. L. Hayes

What would you say to a morning news bulletin that indicates that humanity has made an actual connection with an extraterrestrial race? Not just speculation based on perhaps a promising spectral analysis of a planet indicating liquid water, but an actual message from afar. That message, whatever it said, even if it were a simple “hi,” would cause a profound change on Earth, ranging from our geopolitics, relationships, science, religion, and even beyond.

The search for extraterrestrial intelligence (SETI) encompasses all research methods used by scientists to detect evidence of an extraterrestrial civilization. The most common method utilized is the monitoring of radio waves against the enormous background of “noise” in the universe, which will be the focus of this essay.

There are certainly other methods out there, such as the discovery of an extraterrestrial technosignature such as a Dyson sphere. A Dyson sphere is a theoretical superstructure first hypothesized by physicist Freeman Dyson. He proposed that as a civilization grows and becomes more complex, energy requirements will increase (we only have to look at data centers in our society as an example of energy use that is expected to expand). As a result, Freeman reasoned, an alien civilization may build a structure around its central star to allow for the collection of all of the energy output of a central star. Such a structure would change our view of that stellar system quite dramatically.

Interestingly enough, SETI has a history as old as radio itself, whose invention in 18895 was credited to Guglielmo Marconi, who sent and received Morse code radio signals with it. A mere year later, it was Serbian engineer Nikola Tesla, who, amongst many inventions, is credited with the use of alternating current for electrical transmission in our power grids today. He suggested using radio to contact the intelligence thought to exist on Mars at the time. In 1899, he believed he had received a static signal from Mars that only cut off when the planet set. From what we know about Mars today, it is unlikely that the signal, though authentic, was due to intelligent Martians but rather to a number of other possible causes, including radio signals from Marconi’s continued experiments with radio.

In the March 1955 issue of the popular science magazine Scientific American, author John D. Kraus suggested that we could scan the universe for natural radio waves with a new type of telescope. He gained approval for his new telescope design from Ohio State University, which built the Ohio State University Radio Observatory in Delaware, Ohio, beginning in 1956. It was dubbed “Big Ear,” and it became the longest-running full-scale SETI project in history, from 1973 to 1995. Later SETI programs would expand the spectrum beyond radio and microwaves to include optical wavelengths, searching the cosmos for laser signals.

It was in 1960, however, that the first true organized SETI program was carried out by Cornell University astronomer Frank Drake. He called it Project Ozma, named after the Queen of Oz in L. Frank Baum’s series of books, including the classic The Wizard of Oz. He used the radio telescope at Green Bank, West Virginia, to conduct his study, focusing on the part of the radio spectrum dubbed the “waterhole.” Drake was ahead of his time, as it was only in 1971 that American engineer Bernard Oliver theorized that the “waterhole,” which he also named, would be the likely bandwidth used for communication with extraterrestrials. The name “waterhole” comes from the idea that a waterhole is a place where different species gather.

The waterhole occupies the part of the electromagnetic spectrum that corresponds to radiation from hydroxyl radicals and hydrogen, the components that make up water. Despite water’s relative abundance in the universe, it is a very “quiet” part of the electromagnetic spectrum, which is why bandwidth was chosen. Needless to say, nothing was found. SETI aside, the relative “quietness” of the frequency is why it is used in many other radio astronomy projects today.

NASA put some of its fiscal firepower behind a SETI study in 1971 headed by none other than Drake and Oliver. They were to develop a program that would allow SETI to truly thrive and, hopefully, succeed. The report stated that, to be successful, an array of 1500 dishes from Earth-based radio telescopes would be built at a price tag of ten billion dollars. Needless to say, the report only made it to a shelf labeled Project Cyclops. NASA would continue to fund SETI projects during the 1970s and beyond, but certainly not up to the standards set in Project Cyclops.

SETI was not seen as an essential program by Congress, particularly Senator William Proxmire. Funding was pulled from NASA’s SETI program in 1981, only to be restored a year later through negotiations between astronomer and science communicator Carl Sagan and Senator Proxmire. In 1993, Congress mustered the courage and finally withdrew all funding for SETI programs. Subsequent SETI programs would now fall into the hands of private funders.

Fortunately, in 1984, the SETI Institute was founded by Tom Pierson and astronomer Dr. Jill Carter. It has been headed by astronomer Seth Shostak since 2001. The mission of the Institute was to explore, understand, and explain the origin and nature of life in the universe, with a focus on the search for extraterrestrial life. It is based in Mountain View, California. Beyond sponsoring programs to survey the heavens for an extraterrestrial signal, the Institute also conducts extensive public outreach to inspire new followers in the search for extraterrestrial intelligence. In 2025, the SETI Institute also described a plan to use artificial intelligence (AI) to identify radio and microwave signals that might be intelligent. They have tested their system to determine whether their AI can distinguish background radio noise from that of a well-known pulsar. The AI system passed the test. This would certainly speed up the process of locating that elusive signal from an alien civilization.

Another ally of SETI is the Berkley SETI Research Center, which looks for both optical and other electromagnetic emissions from extraterrestrial civilizations. The center has its headquarters at the University of California, Berkley. It is independent of the SETI Institute, but they do have a common goal and work well together.

One of the projects that the Berkley SETI Research Center and the SETI Institute worked on together led to the creation of the Allen Telescope Array in 2007. Though NASA rejected the earlier concept of Project Cyclops, the Allen Telescope Array is a miniaturized version comprising 42 dishes at the Hat Creek Radio Observatory in northern California. It is still in operation today.

SERENDIP, an acronym for "Search for Extraterrestrial Radio Emissions from Nearby Developed Intelligent Populations," was set up in 1979 (and is still operating) by the Berkley SETI Research Institute. It works by leveraging mainstream radio telescope studies, first at the large Arecibo telescope in Puerto Rico and then at the Green Bank telescope in Green Bank, West Virginia. It attaches its data collection devices to telescopes, allowing SETI researchers to collect the data they want while other astronomers study other phenomena in the universe.  

In July 2015, a ten-year initiative with a price tag of $ 100 million was launched by the Berkeley SETI Research Center. They called it Breakthrough Listen. It currently uses two radio telescopes on opposite sides of the globe, one at the Green Bank Observatory in West Virginia and the other at the Parkes Observatory in New South Wales, Australia. The data received was so massive that, despite only about 24 to 36 hours of telescope time being dedicated, special hardware had to be built to analyze it.

An interesting idea came out of the Berkley SETI Research Institute to address the problem of all the data received by SETI programs. Why not use home computers? We all have screen savers on our computers. SETI@home was set up to utilize this computer's downtime to analyze data.  Any member of the public interested in working with SETI data could sign up and download the program. After only ten years of data collection, SETI@home listened for radio emissions at every point in over 67 percent of the sky. The program ended on March 31, 2020, after 14 years of operation, mainly because managing distributed data required extensive front-end work.

A private program was set up in 1982. It was a low-cost program that used electronics available at any electronics store. Unfortunately, the program was decommissioned on December 4, 2021. The dataset is still available on their website at SETI.net.

Another private startup, SETILeague, was founded in 1994. It comprises members, both amateur and professional, participating in SETI efforts across 62 countries. There is absolutely no government funding for the group, but it comes from membership dues and donations. The founders proposed that searchers could use television dishes three to five meters in diameter and convert them into radio telescopes to detect microwave radiation of intelligent origin. Approximately 5,000 dishes are used worldwide today.  By coordinating the global network, the league can obtain simultaneous coverage of the entire night sky. The coordinated project is called Project Argus. It is aptly named after the Greek mythical guard beast with 100 eyes that could see all directions at once.

Gregory Benford wrote SETI for Profit, which describes a billionaire-funded SETI project that receives a signal but refuses to share the information. The scientific and political communities respond by creating new SETI programs, all to verify the initial supposedly received signal. It is eventually discovered that the signal was a hoax perpetrated to force the political and scientific communities to take SETI more seriously and to sponsor and participate in more initiatives.

Americans are not alone in their search for that elusive intelligent alien signal.  In 2011, the Chinese built the 500-meter Aperture Spherical Telescope (FAST). Part of this large project is to detect those alien transmissions.  After only eleven years of operation, the program bore fruit as some supposedly alien signals were detected. As is the wont of the scientific community, it was quickly beaten down, indicating that the signals were due to radio interference. However, others have stated that further studies should be done to determine the origin of the signal.

Perhaps the most famous promising signal from afar is the WOW! signal detected by the Ohio State SETI program on August 15, 1977. A project volunteer, Jerry Ehman, noticed a strong signal being received by the telescope that stood out against the background radio noise.  He circled the spot on the printout and wrote WOW! in the margin. It is the best evidence of extraterrestrial communication, but unfortunately it has not been received again despite further searches.

In addition to passive listening to the stars, there have been controversial active SETI programs. Essentially, instead of listening to the stars, they actively send signals into space in the hope that an alien civilization will intercept them. The first one was sent out in November of 1974 from the Arecibo Observatory, known as the Arecibo Message. It was sent to the globular cluster M13, which is 25,000 light-years from our planet. Ukraine has been very busy, having sent a number of signals called Cosmic Call (1999), Teen Age Message (2001), Cosmic Call 2 (2003), and A Message From Earth (2008), all from the Yevpatoria Planetary Radar in Yevpatoria, now under Russian control.

A recent addition to the private organizations participating in SETI is METI International (METI). It is an organization based in San Francisco founded in July 2015 by American astrobiologist Douglas Vakoch. In October of 2017, it sent a series of messages to Luyten’s Star which is about twelve light-years away, to Ross 128 at a distance of eleven light-years and HD 164595 which is 94 light-years from Earth (HD 164595 was the source of an unlikely message from afar in 2015 since the energy required for the signal generation would equal that of all the energy that the Earth currently uses). No search to date has indicated any intelligent response.

It’s one thing to receive extraterrestrial signals, but sending signals out has a number of detractors. Physicist Stephen Hawking suggested that alerting aliens to our existence is foolhardy and used examples of European powers that met with aboriginal societies of the Americas, Australia, Africa, and Asia as examples where things went badly, despite, at least in some circumstances, the best of intentions. Astronomer and science fiction writer, David Brin, has articulated similar thoughts.

Robert Sawyer’s Flashes describes the receipt of an alien message full of information that has a negative impact on our planet, in the form of depression, suicide, and violence. In Cixin Liu’s The Three-Body Problem, the protagonist is a political outcast who also happens to be an astrophysicist. During the Cultural Revolution, she is sent to work on a secret military program to search for and communicate with aliens. When an alien transmission is found, the protagonist sends out a message, inviting the aliens to help Earth settle its problems. In fact, The Three-Body Problem is the first of a trilogy (The Dark Forest and Death’s End) that describes an eventual invasion of our Earth and our ultimate salvation through escape from our planetary confines.

Others, such as astronomer Jill Tarter, have argued that aliens who have developed the ability not only to communicate but even to travel across interstellar distances would only have been possible in a cooperative society, not one formed through violence. Then again, through the reading of a lot of science fiction or watching science fiction movies, people might have reason to be fearful. Advanced societies seem to evolve from highly territorial and violent cultures. Even Earth’s history has examples of expansionist and violent civilizations, such as Rome.

What to make of this silence in the heavens? This is also known as the Fermi Paradox, first formulated by physicist Enrico Fermi, who worked on the Manhattan Project, who asked: “Where are they?” With the SETI program, it has been called “The Great Silence.” There are a number of reasons for the silence. Perhaps we are not looking in the right part of the spectrum. Maybe aliens are not interested in communicating with us, using Hawking’s and Brin’s argument. Possibly, they don’t have the technology to communicate, or perhaps they have destroyed themselves. Then again, advanced civilizations might be extremely rare in the cosmos. Who knows? We only have our planet to look at for an example.

Perhaps one of the most interesting solutions to the Fermi Paradox in relation to SETI messages comes from Robert Sawyer’s You See, but You Do Not Observe. You have to appreciate the Sherlock Holmes detective series by Arthur Conan Doyle. Doyle wanted to kill off his popular character, but there was an enormous backlash by his fans. The public's rejection of Holmes’ death leads Earth to fall into an alternate universe. Earth must re-sync to detect alien radio transmissions.

One of the first stories about SETI was written by James Gunn entitled The Listeners. It explores the impact of receiving an alien signal at the personal and societal levels. Chloe Zerwick and Harrison Brown’s The Cassiopeia Affair captures the politics that would ensue from a message being received by an alien civilization. It is set in the near future with the world on the brink of nuclear annihilation. Zerwick’s tale brings out two possibilities for the message: one that prompts discussion about world peace, and the other about the potential exploitation of the message. Jack McDevitt, in The Hercules Text, also explores the world's reaction through a number of characters to the interception of an alien message. McDevitt also wrote the short story, Nothing Ever Happens in Rock City, which follows the impact of receiving an alien message from the point of view not of a country or society, but of the owner of a liquor store that happens to be close to the observatory.

Some authors have written about the receipt of an alien signal that actually encodes information for humanity. In Carl Sagan’s only fictional book, Contact, a young idealistic astronomer discovers a signal from Vega that contains instructions on how to construct an advanced spacecraft. A for Andromeda and its sequel Andromeda Breakthrough, jointly written by Fred Hoyle and John Elliott, follow the receipt of instructions from the distant Andromeda Galaxy for the building of an advanced computer system. Robert Sawyer, in his Factoring Humanity, describes a psychologist working to decode a message from Alpha Centauri. As the story evolves, the secrets contained in the message become more and more intense. In Robert Sawyer’s Rollback, Earth receives a message from a star that is nineteen light-years from the Earth. It turns out to be a survey on morality. When the Earth responds, it receives instructions for the incubation of two alien babies.

What about deciphering the message? The WOW! message may have been a message for all we know, but how to decipher what has been sent? Stanislaw Lem’s His Master’s Voice follows the interplay between a group of scientists tasked with figuring out exactly what the received message is saying.

Then there are those writers who suggest that SETI might just be looking in the wrong place. In John Walker’s We’ll Return, After This Message, an alien message is found not in the cosmos but in the human genome. Oliver Morton’s The Albian Message follows a very similar theme, suggesting that the best place to look for an alien message is in the human genome.

Other authors have looked at the possibility of intercepting a signal from afar that might not be meant for us, but is instead sent out as something of a mass email. In Stephen Baxter’s short story, Last Contact, scientists are finding more and more messages from the heavens. When they finally decipher it, the message is a goodbye, as the Universe is undergoing its demise in the form of a Big Rip. The Big Rip is a hypothetical end to the Universe in which its continued expansion reaches a point where not only does space expand at an ever-increasing rate, but even the atoms that make up everything are torn apart. Gregory Benford’s Dance to Strange Musics follows an expedition to Alpha Centauri where the explorers discover a planet-wide collective lifeform that is sending messages out containing vast amounts of information to one star after another.

What about the receipt of our messages? How will they be received by aliens? In Terry Bisson’s They’re Made out of Meat,” our messages are being received by alien machine intelligences. They are unable to deal with the source of the message, finding that we are made out of “meat.”

What would happen if SETI messages became commonplace? Some authors have explored this. Hydrogen Wall by Gregory Benford describes a huge library for handling all the SETI messages coming in. He also wrote Shadows of Eternity, which describes a SETI library on the moon whose mission is to decipher the many messages from the cosmos. Interestingly, the twist is that many of the messages are coming from artificial intelligences. Alastair Reynolds took the multitude of incoming messages in a different direction. In Feeling Rejected, the messages are so abundant that they actually become boring.

The silence of the heavens is deafening. We can only wait patiently for that elusive whisper from the Universe. Not only would such a discovery—and many scientists believe it is only a matter of time—allow humanity to learn about an alien intelligence, but the greater impact will be that we learn far more about ourselves.

References

1. Basalia, George. 2006. Civilized Life in the Universe: Scientists on Intelligent Extraterrestrials. Oxford University Press.

2. Caballero, Alberto. 2022. An approximation to determine the source of the WOW! signal. International Journal of Astrobiology. 21(3):129-136.

3. Cocconi, G. and Morrison, P. 1959. Searching for interstellar communications. Nature. 184(4630):844-846.

4. Drake, Frank and Sobel, Dava. 1992. Is Anyone Out There? Delacourt Press.

5. Ehman, Jerry and Shuch, H. Paul (eds). 2011. Searching for Extraterrestrial Intelligence: SETI Past, Present and Future. Springer.

6. Garber, S. 1999. Searching for Good Science: The Cancellation of NASA’s SETI Program. Journal of the British Interplanetary Society. 52(1):3.

7. Gertz, J. 2016. Reviewing METI: A critical analysis of the arguments. Journal of the British Interplanetary Society. 69:31-36.

8. Gray, Robert. 2012. The Elusive WOW. Search for Extraterrestrial Intelligence. Palmer Square Press.

9. Gray, Robert and Marvel, Kevin. 2001. A VLA Search for the Ohio State ‘WOW.’ The Astrophysical Journal. 546(2):1171-77.

10.  Haramia, C. and DeMarines, J. 2019. The Imperative to Develop an Ethically-Informed METI Analysis. Theology and Science. 17(1):38-48.

11.  Harp, G. et al. 2016. SETI Observations of Exoplanets with the Allen Telescope Array. The Astronomical Journal. 152(6):181.

12.  MacMahon, D. et al. 2017. The Breakthrough Listen Search for Intelligent Life: A Wideband Data Recorder System for the Robert C. Byrd Green Bank Telescope. Publications of the Astronomical Society of the Pacific. 130(986):044502.

13.  McConnell, Brian and Toporek, Chuck. 2001. Beyond Contact: A Guide to SETI and Communicating with Alien Civilizations. O’Reilly Media.

14.  McDonough, Thomas. 1987. The Search for Extraterrestrial Intelligence: Listening for Life in the Cosmos. John Wiley and Sons.

15.  Moldwin, Mark. 2004. Why SETI is science and UFOlogy is not. Skeptical Inquirer. 28(6).

16.  Morrison, David. 2006. Astrobiology Is the New Modern Framework Encompassing SETI…and So Much Else. Skeptical Inquirer. 30(3).

17.  Oberhaus, Daniel. 2019. Extraterrestrial Languages. The MIT Press.

18.  Preiss, Byron. (ed). First Contact: The Search for Extraterrestrial Intelligence. Bantam Books.

19.  Preiss, Byron and Bova, Ben (eds). 1999. Are We Alone in the Cosmos? The Search for Alien Contact in the New Millennium. Ibooks.

20.  Sagan, Carl. (ed). 1973. Communication with Extraterrestrial Intelligence (CETI). MIT Press.

21.  Schenkel, Peter. 1999. Are We Ready for It? Minerva Press.

22.  Schenkel, Peter. 2006. SETI Requires a Skeptical Reappraisal. Skeptical Inquirer. 30(3).

23.  Siemion, Andrew et al. 2012. The Allen Telescope Array Fly’s Eye Survey for Fast Radio Transients. The Astrophysical Journal. 744(2):109.

24.  Sullivan, W. 2004. Message in a bottle. Nature. 431(7004):27-28.

25.  Swift, David. 1993. SETI Pioneers: Scientists Talk about Their Search for Extraterrestrial Intelligence. University of Arizona Press.

26.  Tarter, Jill. 2006. The Cosmic Haystack Is Large. Skeptical Inquirer. 30(3).

27.  Tarter, Jill et al. 2011. The first SETI observations with the Allen telescope array. Acta Astronautica. 68(3-4):340-346.

28.  Townes, C. 1983. At what wavelength should we search for signals from extraterrestrial intelligence? Proceedings of the National Academy of Sciences. 80(4):1147-1151.

29.  Vakoch, D. 2017. Hawking’s fear of an alien invasion may explain the Fermi Paradox. Theology and Science. 15(2):134-138.

30.  Ward, Peter and Brownlee. 2000. Rare Earth. Copernicus.

31.  Welch, Jack et al. 2009. The Allen Telescope Array: The First Widefield Panchromatic, Snapshot Radio Camera for Radio Astronomy and SETI. Proceedings of the IEEE. 97(8):1438-1447.

32.  White, Frank. 1990. The SETI Factor: How the Search for Extraterrestrial Intelligence is Changing Our View of the Universe and Ourselves. Walker and Company.

33.  Willis, Jon. 2016. All These Worlds Are Yours: The Scientific Search for Alien Life. Yale University Press.

34.  Zuckerman, Ben and Hart, Michael (eds). 1982. Extraterrestrials: Where Are They? Elsevier Science & Technology Books.