Since long before humans mastered the art of space flight, we’ve gazed in awe at the stars and wondered: Are we the only intelligent life in the universe? Modern breakthroughs in technology have allowed us to look and listen farther and deeper into the universe than ever before, and many astronomers believe that it’s a mathematical improbability that we on Earth are alone in the universe. But if there is extraterrestrial intelligence (ETI), wouldn’t “they” be able to contact us? Wait—aren’t they already contacting us?
Two physicists out of Laval University, Quebec, caused a stir earlier this month when they published an analysis of “strange modulations” coming from a subset of over 2.5 million stars earlier this fall in the Publication for the Astronomical Society of the Pacific, stating they were “probably” from aliens. It wasn’t the first such finding from the author of the paper—four years ago, Ermanno Borra, a professor of physics at Laval University, published research in the Astronomical Journal predicting that if ETI want to let us know they are there, there would be a simple method for them to do so.
A more advanced civilization would have even more powerful light sources to communicate farther distances.
“They can send pulses of light, like a flashlight turned on and off, but with a laser,” Borra says. These flashes of light, he theorized, would be very close together, one-millionth of a second apart. Similar technology already exists here on Earth, says Borra, but our most powerful lasers could only send such a message about 1,000 light years away. “A more advanced civilization would have even more powerful light sources to communicate farther distances.”
To test the hypothesis of his last paper, Borra and his graduate student E. Trottier analyzed a spectrum of 2.5 million objects in the sky publically available from the Sloan Digital Sky Survey. “We found exactly the kind of signal I had predicted out of only 234 stars that look like our sun,” Trottier says. These sun-like stars “are not identical twins, but in a temperature range similar to the sun’s. We would expect that if life exists somewhere in our galaxy, it’s on a planet like Earth which rotates around a star like our sun.”
That the signals matched his earlier published theory in such a small number of stars, he says, “suggests strongly that the signals come from ETI.” Trottier claims to have done very careful work to “make sure the signals were not artificial, or generated by the instrumentation. “The very detailed analysis showed that is not the case,” he says, though the team’s paper states, “Although unlikely, there is also a possibility that the signals are due to highly peculiar chemical compositions in a small fraction of galactic halo stars.”
If these strange modulations are, in fact, the communication of an ETI, it’s likely to be one much more advanced than our own civilization by “thousands of years” he says. “We do not have the technology now to communicate with them, though we do have the technology to analyze the signals.” Moreover, Trottier theorizes that it’s possible that encoded within those light pulses could be other information. “They could change the intensity of the signals, or the separation between the pulses to send information about themselves,” even using images, he says.
Though Borra is enthusiastic about his results, he says that right now, his very exciting paper is founded on a hypothesis—not proof. “The next step is to use a powerful telescope to analyze the signals,” he says. He is waiting for “the reaction from the scientific community, because I can’t do it alone.”
Seth Shostak, Senior Astronomer at the SETI (Search for Extraterrestrial Intelligence) Institute—an organization dedicated to finding evidence of ETI—expresses doubt about the nature of those signals. “It’s really hard and inefficient to change the light output of a star,” he says, comparing it to a kind of Morse code on an enormous scale. “You’d have this huge device which only gives you a few bits per second. Does that make a lot of sense?” Add to that the fact that if 234 stars were all sending these signals, that would require some sort of broadcast arrangement between societies hundreds or even one thousand light years away.
“On the other hand, who knows what the aliens do. Nobody knows,” he says. More interesting to him is whether Borra and Trottier can substantiate their claim, and if others will be able repeat their analysis in a meaningful way.
You have to be careful not to jump the gun.
Over the summer, SETI received numerous media calls after Russians found a similarly unusual radio signal. “It turns out it was just a satellite,” Shostak says. “You have to be careful not to jump the gun. You don’t want to throw the baby out with the bathwater by ignoring everything, but on the other hand, every time astronomers turn up something new, people suggest it’s alien activity.”
This doesn’t mean that Shostak is doubtful that intelligent alien life exists, given that “there are a trillion planets in the Milky Way galaxy, and we can see 100 billion other galaxies, each with a trillion planets.” However, he suggests that if there really were something new and exciting discovered, “it wouldn’t be just a story on a website somewhere. There would be press conferences. You would see it on the front page of The New York Times.”