It’s been forty years since Carl Sagan’s novel, Contact, was published amidst a blaze of publicity, hype and genuine curiosity about what arguably the world’s greatest ever science communicator had concocted.

It’s the story of a SETI researcher whose project discovers a signal from an extraterrestrial civilization, a message with instructions to build a device of unknown purpose, believed to be a means of transport to take a small crew to meet the aliens. Dig deeper, however, and you’ll find a tale that considers the meaning of life and God, of humanity’s place in the Universe, in the conflict between science and religion, and of an author longing to see his late father again.

Such was Sagan’s star power that, in 1981, he received a $2 million advance from Simon & Schuster to write Contact. Sagan must have had a hell of an agent: at the time it was the largest advance ever given to an author for a book that had not yet been written. But Simon & Schuster’s faith in Sagan’s novel was well-rewarded; in the first two years after publication in September 1985, Contact sold 1.7 million copies worldwide.

Further popularity lay ahead when, in 1997, Contact was adapted into a Hollywood blockbuster directed by Robert Zemeckis and starring Jodie Foster. Sadly, Sagan passed away the year before.

Contact isn’t just a science fiction book about alien contact; it’s also a depiction of a possible future around the turn of the millennium from the viewpoint of the early 1980s, and it’s fascinating to compare how Sagan saw the near-future to how it actually turned out. I suspect he may have been disappointed in our lack of progress.

The search for extraterrestrial intelligence is at the heart of Contact – its main character, Ellie Arroway, is the director of a massive SETI project, and Sagan delves deep into the technicalities of funding and conducting such a search. In real life, SETI continues listening and looking at the stars with guaranteed funding for years ahead, although perhaps not meeting the levels of investment on depicted in Contact. Perhaps the novel, followed by the film, percolated through the public’s consciousness to have an influence, at least in part, on the acceptance and growth of SETI as a serious scientific field.

There’s a lot in Sagan’s novel to dissect, so we’ll do so in four sections.

In the novel, the alien signal is picked up by the fictional Argus Array – a network of 131 telescopes scattered across the New Mexico desert. In the 1997 movie, the alien signal is detected by the 27 radio telescopes of the Very Large Array (VLA), which is a real radio interferometer that’s also in New Mexico, and which produced one of the movie’s key iconic visuals of Jodie Foster listening with her head phones while sat on her car, the VLA’s dishes serving as an impressive backdrop. The iconic scene became the movie's poster.

Yet, ironically, in 1997 the VLA didn’t even do SETI – it has only been in recent years, since 2020, that the VLA has been utilized in partnership with the SETI Institute.

The fictional Argus Array was probably inspired by Project Cyclops, which is the result of a design study from a NASA SETI workshop in 1971, chaired by Barney Oliver and John Billingham. Bob Dixon, who directed the Ohio State SETI program that discovered the infamous Wow! signal, described Project Cyclops as the greatest radio telescope never built. It would have featured a thousand radio dishes each 100-meters in diameter – in other words, a thousand Green Bank Telescopes – contributing to a total collecting area of about ten square kilometers, eclipsing even the Square Kilometer Array.

As an aside, there was a real-life Project Argus, which was a network of amateur radio dishes spearheaded by the SETI League. The aim was to fill the network with 5,000 stations in what the SETI League described as the most ambitious SETI project ever undertaken without government equipment or funding. Unfortunately, the project peaked in the early 2000s with 142 amateur stations. In 2024 the SETI League announced that they were winding down operations, and their final newsletter was issued in the early months of 2025 as their surviving founding members retired.

In Sagan’s fictional world, SETI has a radio telescope array that astronomers could only dream about. In the novel this leads to tensions with certain sections of the astrophysics community, spearheaded by ardent Argus critic Dave Drumlin who believes that such a facility should be used for more ‘mainstream’ astronomy.

“There are first-rate projects that aren’t finding telescope time … because this facility – by far the best phased array in the world – is being used almost entirely for SETI … this is pandering to UFO kooks and comic strips and weak-minded adolescents,” he moans.

The idea that SETI shouldn’t even be considered real science was prevalent not just back in the 1970s and 1980s, but even as recently as 2009 when Nature’s editors described SETI as having “always sat at the edge of mainstream astronomy … partly because, no matter how scientifically rigorous its practitioners try to be, SETI can’t escape an association with UFO believers and other such crackpots. But it is also because SETI is arguably not a falsifiable experiment.”

Such short-sighted criticism seems out of place today, with astronomers and scientists routinely talking about alien life. The winds of change have undoubtedly come from the massive exoplanet industry that makes no bones about searching for habitable worlds.

As for falsifiability, this is an old argument that even Sagan, through his character Arroway, addressed in Contact. In response to Drumlin, she passionately declares that “If we fail, we learn something of the rarity of intelligent life … and if we succeed, we hit the cosmic jackpot.”

The initial detection in Contact is a burst of radio waves communicating prime numbers – i.e. integers that can only be divided by one and themselves, for example 1, 2, 3, 7, 11, 13 etc. The order of the prime numbers is seemingly random, but they hide several layers of complexity that is embedded within the changing sequence of numbers. First there’s a replay of the television broadcast of Hitler at the 1936 Munich Olympic Games, just to get our attention before the signal begins churning out blueprints for a mysterious machine that proves to be a transport for venturing through wormholes.

Sequences of prime numbers do not occur naturally, and so a signal encoded in prime numbers would instantly tell us that it is artificial in origin.

A message encoded in prime numbers would also tell us something else, which is that on a basic level the aliens must have similar mathematic and scientific disciplines. Indeed, a fundamental conceit of SETI is that the aliens will be using science that, even if we don’t understand it, is a direct progression from our current scientific understanding. Many philosophers of science argue that science and mathematics are universal, independent of space and time and are the same for everyone, everywhere.

However, another school of thought is that human science is a human invention, and that our mathematics is parochial rather than universal. Take prime numbers: we place importance on them because we place importance on whole integers. Perhaps to another technological species with a wholly different evolution and culture, fractions are more important, or they interpret numbers in different ways.

Sagan’s aliens are very much purveyors of the same kind of science and mathematics that we humans understand, to the point that they make it relatively easy for us to build a machine that can travel down a wormhole – even though the characters have no idea that is what it is for. The point is that math provides a common language with which they can communicate with us. Will it be the same in real life? Until we meet them, we have no idea.

If, at long last, we should detect a radio signal from another civilization among the stars, answering the ages-old question of whether we are alone, how should we feel about it?

SETI researchers have tried brainstorming what people’s responses might be, and opinions have varied from real-life contact being an epochal event that transforms society, to it being greeted with a shrug of the shoulders and people just getting on with their lives. Ultimately we don’t know for sure how people and governments would respond until it happens, but suggesting that there would be a mixture of responses seems like a safe bet.

The mixed response is the direction that Sagan takes in Contact. There’s the scientists, who just want to embrace the message without giving other concerns too much thought. There’s governments, politicians and the military, eager to put their stamp on things and use events to their advantage, particularly when there’s hundreds of millions of dollars involved in building the machine in the aliens’ blueprints. Then there is the reaction of the religious, suddenly confronted by something not in their scripture.

There are characters in Contact to provide the viewpoints from each of these communities. The scientists are portrayed as idealists, driven by the pureness of their curiosity – even the skeptical Drumlin quickly comes around when he realizes the message is the real deal. The military are portrayed as suspicious, bordering on paranoid. The politicians are hamstrung by bureaucracy. And the religious viewpoint is treated as largely fundamentalist, believing that the message is the work of the devil. Though these characters are fairly one-dimensional and fit certain archetypes (or should that be stereotypes) to suit the novel, they very efficiently if not subtly convey the idea that a lot of people are going to respond in a lot of different ways to the discovery of a real alien signal.

In 2000 Iván Almár and Jill Tarter developed the Rio Scale (so-named because it was first presented at the International Astronautical Congress held in Rio de Janeiro that year) that aims to quantify the impact on society of different types of possible alien contact. It runs from the lowest impact, nil, to an extraordinary impact of 10 on the scale. There’s a fun Rio Scale calculator that you can assess different scenarios with. A weak omnidirectional broadcast with uncertain credibility requiring further verification would score low on the Rio scale. The signal in Contact – Earth-specific, detected by a SETI radio telescope, from relatively nearby (the star Vega, 25 light years away) and authentically alien without a shadow of a doubt, rates a 9 on the scale (were it from our own Solar System it would have scored the highest impact rating of 10, since it would mean the aliens were already here).

Since 1985, there has been research into how different religions would respond to alien contact, which is a topic that I previously wrote about for Supercluster. While there is still debate among theologians, many are open to the idea of alien life and for them the challenges that it will pose to their faith are surmountable. Certainly, Contact does not present a well-rounded view of how religion might respond, concerning itself mostly with just Christian fundamentalists.

The military paranoia, however, could be much worse than Sagan anticipated. In his novel, military figures are controlling of the project, intent on locking down anything that doesn’t fit the narrative that they want to present to the world at large. However, the detection of the message and the subsequent cooperation between nations to build the alien machine leads to a rapprochement between the Cold War powers.

Things might work out differently if a recent paper by Ken Wisian and John Traphagan is correct. In a previous article, I wrote about how they suggest that the detection of an extraterrestrial signal by one nation could spark an arms race between opposing nations through the perception that the message might contain important technological information. How would other nations know that the country that detected the message isn’t hiding some of its information to keep for themselves?

However, in a strong rebuttal, Jason Wright, Chelsea Haramia and Gabriel Swiney pour cold water on the idea, because it’s unlikely the signal could be kept secret. A signal would first have to be verified by another observatory elsewhere in the world, to prove that it’s not local radio frequency interference, and that means sharing the coordinates on the sky from where the signal seems to be coming from, and this is exactly what happens in Contact. Every nation on Earth tracks the signal, gathering parts of the message to share with each other.

The optimistic outlook does rely on scientists’ first instinct being to share receipt of the signal. In countries with more secretive governments, such as China and Russia, this may not always be the case. Contact shows us the ideal best scenario, with everyone working together and coming closer together as a result. We have to make sure that if we ever detect an alien signal, the same spirit of cooperation is fostered in real life too.

The latter stages of Contact are where it ostensibly turns from a near-future thriller into pure science fiction. A crew of five, including Arroway, are whisked away by machine on a journey through wormholes and between star systems, from Earth to Vega to the near the center of the galaxy, where they dock with a huge, sprawling space station. It’s heavily inspired by Arthur C Clarke’s novel of 2001: A Space Odyssey, in which the Monolith transports Dave Bowman across space to what Clarke describes as the ‘Grand Central Station of the Galaxy’ – Sagan even names one of his chapters after the New York terminal.

In Contact, having entered the space station, the crew of five find themselves on a simulation of a tropical beach, and they each meet an alien in the guise of a loved one. In Arroway’s case – after some unwillingness, which seem strange after she has come all that way – the alien comes to her with the appearance of her late father. He tells Arroway that he’s from a kind of Office of the Galactic Census, collecting information on other species, while his civilization, which is made up of a large number of species from many worlds, is performing some indescribable astro-engineering project at Cygnus A, which in reality is a powerful radio galaxy.

It’s been the hope of SETI practitioners, all the way back to the beginning with Frank Drake and, indeed, Sagan who was at the very first SETI conference at Green Bank in 1961, that there is an interstellar civilization of worlds out there that we might one day join. It has even been posited as an explanation for the Fermi paradox – that we are in some kind of ‘galactic zoo’ maintained by this galactic civilization, possibly to enforce a kind of ‘prime directive’ of non-interference. 

In Contact, the aliens say they reached out to us because we are in a troubling period in our history, but that we display a remarkable adaptability that may yet see us survive. While they don’t offer concrete help or technology, this concept of extraterrestrial civilizations helping us is a popular one among SETI scientists, and was an idea Sagan himself espoused, in both fiction and in his factual writings about SETI.

Contact was published at the height of Carl Sagan’s fame, and its reputation and popularity reflects that. Objectively, it’s not the greatest science fiction novel of all time – too often Sagan slips into lecture mode in his prose, and his characters are mostly one dimensional other than Arroway, who isn’t the most likeable character, coming across as having a smug arrogance that she actually reflects on towards the end of the novel. Nevertheless, Contact is engaging, channeling the charisma of its author. Despite being 40 years old, its scientific ideas are not dated or quaint; if anything, they still hold up today. Though its themes have had four decades to develop further, this actually works in the novel’s favor, making it even more pertinent.

Would Contact gain the same adoration from readers had it been released today? It’s hard to say. There are no more scientific celebrities who are household names like Sagan was – Neil deGrasse Tyson and Bill Nye, former students of Sagan’s, possibly comes closest.

Sagan was a polymath who was an excellent communicator and whose interests in alien life and space exploration were shared by many of the public, which meant that there was eager anticipation for Contact ahead of its release. While it has undoubtedly been Sagan’s star power that helped sell so many copies over the years, Contact has its own intrinsic merit that has allowed it to stand the test of time.