Imagine that you’ve lived your entire life in a small village deep within a continental wilderness. For centuries this community has been isolated from the rest of the world. One day you go out exploring, skirting the edges of known territory. Suddenly, and against all expectations, you stumble across a signpost embedded in the ground. The script is highly unusual, foreign, but the text is clear enough. It says, simply, “We Are Here.”

The question is: What happens next?

There might be happiness and celebration to mark the end of isolation, or the news might be met with a shrug. But human nature suggests it’s more probable that this discovery triggers a chain of events that lead to utter disaster.

Suddenly your safe haven is threatened by an unknown “them.” Your time-tested principles of governance and social order are put under pressure. Gossip, rumor, and conjecture will gnaw away at your stable home. Barricades and armed forces will be raised at enormous cost, crops and repairs will be forgotten. A community will lurch toward its own collapse. Yet there is little more than a half-realized idea represented by this impersonal signpost, a whispered implication that infects the world with its ambiguity.

This tale is not the opening sequence of a B-grade movie, but an allegorical version of what might, just possibly, happen after we solve one of the oldest scientific and philosophical puzzles—whether or not we have neighbors “out there” in the wilderness of the cosmos.

Also in Aliens Why Discovering Martians Could Be Disappointing By Tim Folger While some scientists search for extraterrestrial life by landing rovers on Mars, launching telescopes into space, and scanning the skies with giant radio dishes, geobiologist Joseph Kirschvink thinks that the first telltale signs of alien life may be sitting on...READ MORE





Today, the prospects for finding evidence of life beyond the Earth fall into three well-known categories. First is our exploration of the solar system. Mars is arguably the prime target because it offers a planetary template that, while alien, best parallels certain terrestrial environments—and it is directly accessible. At this very moment we have robotic wheels on Martian regolith and sharp eyes in orbit. More Mars missions are lining up: NASA’s MAVEN should be entering orbit as you read this, as should India’s Mangalyaan craft. And plans are afoot for the InSight seismological probe, Europe’s ExoMars, a Mars 2020 rover, a sample return, as well as the ever-present speculations for sending a human contingent.

But Mars is not the only fruit. The icy moons Enceladus and Europa both exhibit hallmarks of subsurface liquid water. In the case of Europa, a dark ocean with twice the volume of all Earth’s surface oceans conceivably exists in contact with a rocky core—with potential for a deep hydrothermal oasis. Recently discovered geyser-like eruptions into space from both offer hope of a sampling mission to look for signs of life.

In the second category, vastly farther beyond, lie the exoplanets. We now know this population to be enormous—tens of billions of terrestrial-scaled planets ranging from geophysical youth to old age. Some of these worlds could be passable Earth-analogs. The chase is on to measure the atmospheric chemical composition of at least a few of the nearest such worlds, looking for the fingerprints of a biosphere. NASA’s 2018 James Webb Space Telescope and the next-generation of 30-meter diameter Earth-bound astronomical observatories possess the capabilities to make crude measurements of such components.

Third, there is the ongoing search for extraterrestrial intelligence, or SETI. Scouring the celestial radio and optical spectrum for structured, artificial signals—this is the highest-risk, highest-reward effort of all. Success would not only mean that life exists somewhere else, but that there is recognizable technological intelligence other than ours in the universe.

As an information-obsessed, intensely social species, we’re particularly vulnerable to memes. And not all memes

are innocuous.

But the knowledge being sought from all these efforts could change far more than just our scientific understanding. Like a sign in the wilderness, the potential exists for new information to infect our collective consciousness before we’ve realized what’s happening. It is capable of seeding our minds with ideas that take on their own form of life as competitive agents that question the status quo, seeping into our thoughts and behaviors. In fact we already have a label for these types of self-propagating, evolving packets of information—we call them memes.

In 1976, writing in his book The Selfish Gene, evolutionary biologist Richard Dawkins proposed the term meme to describe something that spreads within a culture; whether it’s a catchy phrase, chairs with four legs, a style of clothing, or an entire belief system. In this sense a meme is a mutating, replicating piece of human cultural evolution—a viral entity.

As an information-obsessed, intensely social species, we’re particularly vulnerable to memes. And not all memes are innocuous—some become toxic when they meet other established memes. Witness the clash between Western mores and conservative Islam.

What if we discovered that we are surrounded by chemically incompatible aliens, and learned that all that we thought was inevitable and optimal about our biology and evolution is merely a fluke? Such a discovery runs counter to our Copernican ideals and upends any tidy rationalization of the deep connections between life and the fundamental constituents of the cosmos.

Or what if we detected an extraterrestrial signal along the lines of “You Are All Going To Die?” Even if this was a translation error, or a misinterpretation of an alien effort at existential camaraderie, our species could be quickly sent into a tailspin, potentially wrecking our civilization as effectively as any physical weapon.

Shooting memes back and forth across the void is asking

for trouble.

A message with a more straightforward intent could have equally ruinous effects. It could be a new scientific insight or technological blueprint sent as an item of interstellar trade or détente, but have a destabilizing effect on Earth’s economy. Or a message could contain a philosophical statement interpreted to have religious meaning, triggering conflict and disorder. Even “Is Anyone Out There?” would be problematic—the decision to answer or not could provoke more than just verbal conflict within our species.

We may also agree to reach out, to our own detriment. If we identify the chemical signatures of a biosphere on a nearby exoplanet there will be temptation to send a focused message—a long-shot effort at communication. In our impatience we have already made such attempts. In 1974, for example, the Arecibo radio observatory beamed a meme-laden message of 1,679 binary digits towards a distant globular star cluster. Its contents included a simple string of numbers, a basic blueprint describing DNA, a cartoon human figure, and the layout of our solar system. We’ve also spent decades blaring out our wideband analog radio and TV transmissions before downsizing to digital. With a real target we might even consider sending a probe, especially if we ever develop the means to traverse interstellar space at a substantial fraction of the speed of light.

But these behaviors are terribly dangerous for us if they prompt a response from our cosmic neighbors, as well as for any intelligent natives of these other worlds. Shooting memes back and forth across the void is asking for trouble.





What are we to do? We still want to know whether we’re alone or not. Scientific curiosity and logic surely demands this for any rational entity. It’s a central piece of the puzzle for trying to understand our own origins and nature, our place in the universe.

The answer may lie in building a planetary firewall, a kind of “meme armor” to shield us from damaging knowledge of extraterrestrial life, while still allowing us to learn about the cosmos. It would be an artificial and autonomous construct that would take over the job of SETI, and even the task of exoplanet-hunting astronomers. By providing an algorithmic or physical barrier to the rest of the universe, it would help sift and control the flow of information—rather like an Internet firewall that defends against viruses by scrutinizing the origin and intent of packets of data.

The armor might involve a unilateral ban of private telescopes or radio antenna with enough sensitivity to chance upon extraterrestrial signposts. It could be equipped with its own automated listening posts and telescopes—spoon-feeding sanitized results to its masters. Careful (and hopefully unhackable) firewall programming would sift and sanitize its sightings. The riskiest data could be stored in case of true existential disaster—when an extraterrestrial meme can do no worse damage than is already in progress—a library of last resort for a species, the ultimate example of “In Case Of Fire, Break Glass.”

We’d build a vast Dyson sphere and live on the inside facing our star, sealed away from the infectious cosmos.

Such armor could also present a camouflaged state to onlookers; blocking attempts to discern the presence or nature of life on Earth, much like the hidden host addresses used behind today’s computer firewalls. Or—in a far more sinister version—it could seek to actively infect other worlds with destructive memes in order to reduce potential threats to Earth.

Just as our highest security computer systems are physically isolated from the net, a more ambitious hardware-based armor could veil the Earth’s view of the universe. A giant high-tech Faraday cage made with pixel-like optical elements to control precisely what electromagnetic radiation gets through—an informational version of the air-filtration and containment of a biohazard lab. More drastic still would be to abandon our meme-vulnerable planet altogether. We’d build a vast Dyson sphere—that staple of futurology and sci-fi—and live on the inside facing our star, sealed away from the infectious cosmos.

These are obviously hugely speculative, if not fanciful ideas. Perhaps our form of intelligence actually has a degree of natural immunity to extraterrestrial meme infection. After all, since grasping the concept that we inhabit one microscopic piece of an immense universe with no physical center, our species has not actually self-destructed—at least not yet. Most importantly, I don’t think we should be dissuaded from seeking out the most fecund places in the cosmos, and we’re unlikely to want to ever shield ourselves from the glory of the celestial skies.

But, as the adage goes, we should be careful what we wish for.





Caleb Scharf is an astrophysicist and the Director of Astrobiology at Columbia University in New York. His latest book is The Copernicus Complex: Our Cosmic Significance in a Universe of Planets and Probabilities.