The week of May 17, 2015

The problems with talking to aliens

By Marissa Fessenden

In the constellation Boötes, a star a bit smaller than our sun flares sporadically, dimming and brightening, but still too faint to be seen with the naked eye. Scientists have named this red dwarf Gliese 526 and categorized it as a star that just might have a habitable planet or two. No one has spotted a planet yet, but the abundance of planets orbiting other, similar stars make the chances look good. If life exists in that star system, we would be neighbors: Gliese 526 is a mere 17.6 light years away.

If that life is intelligent, and listening, they just might be the first non-human beings to receive a message from Earth. In the summer of 2013, a small team of scientists and entrepreneurs announced the start of a project they called “Lone Signal.” Using a recommissioned radio dish in Carmel, Calif., the group, led by scientist and musician Jacob Haqq-Misra, would send messages to Gliese 526. Conceivably, some of the senders could get a reply in their lifetimes.

The senders could have been anyone. “From the start we wanted to be an experiment where anyone on Earth could participate,” said Haqq-Misra during a press event on June 11, 2013, according to Universe Today.

One of the first messages, broadcast on June 17, 2013, was from futurist Ray Kurzweil. The Lone Signal project’s Tumblr posted the message:

Whether alien intelligence will be able to understand what Kurzweil means by “The Singularity” is unclear. Presumably some of the other messages were more basic. However, funding woes cut the project short, and its future is uncertain.

The Lone Signal was just one recent attempt at communicating with alien intelligence, an effort often called Messaging Extraterrestrial Intelligence (METI) or Active Search for Extraterrestrial Intelligence (Active SETI) to contrast with passively listening for alien broadcasts. It’s a vibrant, if small, field of work with basis in real science. However, like the Lone Signal project, METI and SETI projects are rife with funding troubles and punctuated by fierce debate. Some experts argue that humans should keep their heads down rather than sending signals into space, lest we call down the wrath of an angry and powerful alien civilization. Others contend that we have a moral obligation to let extraterrestrial beings know they are not alone.

“This is one of those fields of human knowledge and science that has no known subject matter,” says science-fiction author David Brin. Perhaps as a result, the debate can get so passionate that it strays outside the normally civil, dry academic language of other scientific debates. “There’s nothing to analyze and no chance of there being a resolution right away, so as a result anyone can opine anything.”

Yet the subject also brings up grand notions—time, the scale of space, the nature of the universe and life itself.

What’s the point?

The Earth is a busy place. With poverty, war, climate change, disease, and plenty of problems communicating among ourselves, it may strike some as foolish to spend resources looking for aliens at all, never mind sending a message.

Of course, proponents point out that any alien civilization we encounter is bound to be more advanced than humans. Earth, after all, has only been around for about 4.5 billion years, whereas the universe has enjoyed 13.8 billion years since the Big Bang. The early universe would have been a rough place for life to find a toehold, given the abundance of forming stars and high levels of radiation. After it calmed down, however, extraterrestrial life had a few billion years to come on the scene before us.

The subject also brings up grand notions—time, the scale of space, the nature of the universe and life itself.

Seth Shostak is one of the most outspoken proponents of sending a message and the senior astronomer and director of the SETI Institute in Mountain View, Calif. (The institute gets its name from the description of the field as a whole; other SETI efforts aren’t necessarily affiliated with it.) Sure, beneficent aliens could beam us all of physics, but simply knowing that there are others out there would be useful, he contends.

Even just a ping would send the message that “gosh darn it, they made it beyond our own level,” he says. “Maybe we’re not destined to wipe ourselves out quickly.”

Before delving properly into the reasons humans might want contact, it’s important to understand that the notion of aliens existing isn’t crazy. Experts on both side of the debate agree that it doesn’t make sense for humans to be the only inhabitants of the universe. NASA is serious enough about the possibility of alien contact that it’s issued an ebook to help prepare humanity. Given the plenitude of planets and the number of potentially habitable worlds, the reasoning goes, there must be life out there.

Yet, once you embrace the idea of aliens, you have to grapple with what is known as “the Fermi Paradox.” If there are aliens, where are they and why haven’t we found them already? Kurz Gesagt – In a Nutshell presents a good overview of this paradox in a video:

The possible answers to the Fermi Paradox boil down to:

  • Life—intelligent, spacefaring life in particular—is harder to achieve than we realize, making humans part of a very rare group. Possibly, we are the first lifeforms to get this far.
  • There is a super-intelligent group of beings that eliminates any other civilization that becomes advanced enough.
  • We are alone.

A less existentially worrying reason we haven’t heard from ET might be that they’re waiting for us to speak up first, to prove we are advanced enough to hold a conversation. Or perhaps they did initiate with the so-called WOW! signal, which came into a radio observatory at Ohio State University so strongly and inexplicably in 1977 that researchers have sent replies back.

Essentially, the argument for why humans should look for extraterrestrial life and consider sending a message boils down to one thing for Shostak: curiosity. “There’s a tendency to look at curiosity as a luxury,” he says, but a society without curiosity stops changing and growing. “That makes society vulnerable.”

They are far away and don’t understand us

Even if everyone agrees it’s worthwhile to send a message, it’s a daunting effort. The incredible distances in space, and the time it takes to cross them, have essentially rendered most past METI projects useless or mere publicity stunts.

The Arecibo message was one of the most powerful beacons ever sent into space. In 1974, the Arecibo Radio Telescope beamed an encoded pictorial message toward a globular star cluster 21,000 light years away. When it arrives, however, that star system will have moved out of the neighborhood, according to Scientific American. That message will never reach its intended destination.

However, with more powerful transmitters and better ability to predict where systems will be by the time our message gets there, this concern is starting to fade. Instead, the real confusion starts to crop up when considering what message should be sent.

Humans have long been interested in communicating with whoever might be out there. But the messages people propose today can still seem lacking and unintelligible from a hypothetical alien’s point of view. Take, for example, the images etched into the plaque attached to the Pioneer space probe:


A nude man and woman, standing in front of a representation of the spacecraft itself (for scale) may be easily interpretable to humans, but what if the aliens that find the plaque don’t have eyes and instead communicate by smell? Even if they do see, will the lines look like squiggles or like beings? Will they judge us by the quality of the art? The plaque has earned a fair amount of criticism, but the researchers charged with the task—Frank Drake, Carl Sagan, and artist Linda Salzman Sagan—had three weeks to come up with a message. They were happy to get something on the space probe.

More recently, projects like Lone Signal have asked members of the public what message should be sent. “People talk about friendship, love, peace,” says Dimitra Atri, a physicist with the Blue Marble Space Institute of Science who also runs a project called The project centers around a website set up with the idea that if humans around the world practiced sending encoded messages to one another, we might be able to learn more about the challenges of communicating. Atri imagined that he would be able to crowdsource ideas on what message to send, but there is so little funding available for METI the website remains a side project.

Even the Lone Signal project, which didn’t rely on grants for funding, had trouble, despite charging the message senders (25 cents for a tweet-length message, plus more for longer messages). In late August 2013, the project cofounder and CEO Pierre Fabre wrote a letter and posted it to the project’s discussion boards. “Due to our financial challenges, we have had to reluctantly reduce our transmission schedule and now, our latest blow has been software issues that have all but halted transmission over the last two weeks,” Fabre wrote. He promised that any messages queued up by 1am EDT on Aug. 28 would be processed manually. That text remains the most recent post on the project’s Tumblr page. Currently, the Lone Signal’s website returns an error page.

Essentially, the argument for why humans should look for extraterrestrial life and consider sending a message boils down to one thing for Shostak: curiosity.

At least the first messages were beamed and are somewhere in space between here and Gliese 526’s predicted location. Still, the intended recipients are aliens. “Any kind of concept is impossible,” Atri says. “How are we going to communicate any emotion?” A message of galactic peace may be nonsensical to civilizations that don’t have peace as a concept—either because they don’t know its opposite or because they are so aggressive that peace seems naive.

Despite the complex concepts in some of the messages proposed by DearET and Lone Signal participants, Atri and other experts hope that intelligent beings will at least be able to understand the portion of the message called the hailing beacon.

It’s a simple string of numbers designed to be easily decoded, and it was developed by Michael Busch, a research scientist now at the SETI Institute.

Busch explains that the modern field of SETI goes back more than 50 years, to a 1961 workshop convened by astronomer Frank Drake. The questions posed at the workshop (How many habitable planets might be out there? What percentage could give rise to life?, etc.) provide the basis for what is now known as the Drake Equation, a framework for calculating the number of technological civilizations in the Milky Way galaxy.

Drake also created a test message that might be sent to aliens. The entire set of physicists, astronomers and other expert attendees spent a week thinking about Drake’s message. Not one was able to decode it. Busch recalls feeling discouraged when he learned this story (he’s a young researcher). “If we can’t make this message intelligible to each other then how are aliens going to understand?” he asked.

So Busch set out to come up with a message that could be understood. To explain how it works at, Busch wrote a simple set of phrases in numbers. Here it is:


If you’re not a code breaker or a computer programmer, this will probably seem obtuse. But if you realize that “999” means the start of a phrase and “888” means the end of one, it starts to make sense. Here Busch replaces “999” with “(” and “888” with “)” to make the phrases between more obvious:


Now, it might take a leap, but “333” means “equals,” the first real word in this language. Step by step, a common understanding can be built. The next step might be to establish the numerical sequence that means “not equal.” From there, Busch built up sentences that describe a basic understanding of math and physics, information that indicates that humans are intelligent enough to figure out those basics of how the universe works. We are here and we understand (a bit), the hailing beacon says.

The cipher can be sent by varying the frequency of an FM radio signal in a narrow band. Discrete steps up and down from the base frequency represent the numbers 0 through 9. Thus the message’s pattern can be written in radio waves. (FM is better than AM because it can travel farther without degrading.) Once the language is established, two groups of intelligent beings could conceivably exchange ideas.

When Busch first tested his idea with a group of physics and math undergraduates, they decoded the cipher in 12 hours. They even corrected some typos, “which I found encouraging,” he says. Since then, he has developed different, improved versions for and for the Lone Signal Project. (If that example seems accessible enough, take a crack at the test message posted at

The Arecibo Radio Telescope U.S. National Oceanic and Atmospheric Administration
Shostak has a completely different proposal for the message humans should send: Broadcast the entire Internet.

Such a deluge of information may be a way to skip over the trouble of coming up with one message to represent all of humanity. From this perspective, it’s not even necessary to come up with a code and a key that alien intelligence would understand. The contents of the Internet are full of redundancy. As science journalist Tom Siegfried puts it for Science News:

So a sufficiently advanced civilization, well acquainted with analyzing big data, ought to be able to decode the Internet accurately. In which case, two possible responses are likely: The aliens will conclude that Earth should be immediately exterminated, or they will send back the favorite examples of their cat videos.

Sending the whole Internet also means that humans don’t have to decide how truthful to be. The message doesn’t need to reassure that we are not a violent and hostile species, despite our history. It also doesn’t need to confess that history to avoid painting too rosy a picture of our tendencies. Worrying about how we come off is a bit overblown, from Shostak’s perspective.

Shostak has a completely different proposal for the message humans should send: Broadcast the entire Internet.

“I’m not certain that matters much,” he said. “The message takes so long to get to you.” It’s akin to archeologists learning about violence done during the Roman Empire. If the entire Internet is available, aliens can put violence in context with good deeds. They can even ask questions and find the answers without the need for an extended back and forth.

They might be hostile

Of course, even with the whole Internet, aliens may conclude humanity is too terrible to be allowed to survive. Or that our meat bodies sound downright tasty. Even if the idea seems ripped straight from science-fiction pulp novels, it’s not impossible that aliens would come and destroy Earth.

For, Charlie Jean Anders outlines some more plausible reasons that aliens would expend the effort to cross space. They may be eager to find more habitable worlds—which may be more rare than we think—or they may crave some knowledge we somehow possess. “What if our very existence, or something we’ve thought up, is threatening—either politically or ideologically, or on religious grounds? Or even scientifically?” she writes.

The risks concern scientists enough that a 2006 editorial in Nature urged caution before sending a message. After a meeting this year at the SETI Institute that made the polarization of the debate obvious, a group of researchers and interested authorities (including entrepreneur and SpaceX CEO Elon Musk) signed a letter in about Active SETI and METI stating:

Intentionally signaling other civilizations in the Milky Way Galaxy raises concerns from all the people of Earth, about both the message and the consequences of contact. A worldwide scientific, political and humanitarian discussion must occur before any message is sent.

The statement was spurred by the mounting interest among some, including Shostak, in sending transmissions that would be hundreds of times more powerful than any transmissions sent before. Science-fiction author David Brin, among the signatories, calls this approach akin to shouting “yoo-hoo” at the cosmos.

“I’m not claiming that aliens are automatically going to be dangerous,” he says. “I can just say that those who dismiss that out of hand are not being scientific or logical.”

Brin advocates for a serious and open discussion about the risks of transmitting a message. “At a minimum, it would involve some of our best and greatest sages of science, ethics and students of history,” Brin says. “We know of encounters between technological and less technologically advanced civilizations. And these are daunting. Not one of them did not at least result in pain.”

The discussion not only would bring great minds together, but it would also be fascinating and likely bring more interested in the SETI cause itself, Brin adds. “The relentless efforts to keep this topic area restricted to a dozen insular zealots would seem to be self-defeating.”

A discussion offers people a chance to vote. Brin says that since the instruments used to shout at the cosmos are funded by taxpayer dollars, letting one small group speak for the world would mean using our money without our input.

Shostak isn’t certain that a discussion could resolve all concerns, even if the issue is put up to vote. “Say 58 percent says let’s send a message and 42 says let’s not,” he says. “Have we somehow addressed the danger?”

Shostak says he doesn’t know whether aliens are dangerous, but he has strong feelings that we can’t do anything about the risk anyway. Any society advanced enough to travel hundreds or thousands of light years to reach Earth will be able to pick up the very faint signals we have already broadcast, Shostak argues. Even our television and radio signals leak a bit into space; our current technology can’t pick up similar, hypothetical leakage from distant planets, but an advanced civilization could detect ours.

If dangerous aliens are out there, they may find us anyway, whether or not we broadcast a loud and clear, “We’re here.”

Correction: A previous version of this article mis-stated the affiliation of Dimitra Atri. He works for the Blue Marble Space Institute of Science.

Illustration by Max Fleishman