This is one of those stories we have to write from time to time. Over the past week, the internet has been alive with stories like this: "Either Stars are Strange, or There Are 234 Aliens Trying to Contact Us," and "Astronomers Detect Strange Star Signals That Are 'Probably' Aliens Making Contact." There have also been about the same number of articles telling everyone to settle down, like this one from Nature World News: "No, Space Aliens are Not Communicating Through Strange Signals From Stars."
So what's the truth?
The truth — as is often the case — is somewhere in between, and to get to it, VOA spoke with one of the authors of the article that is the genesis of all these headlines.
So where did all this alien talk come from?
Ermanno Borra and E. Trottier from Laval University in Quebec, Canada, released a paper for peer review on October 14. The title, on its face, isn't likely to stop the presses: "Discovery of peculiar periodic spectral modulations in a small fraction of solar type stars." To get an understanding for what that means, we asked Borra to explain.
He says the whole goal of his research was to search the universe for rhythmic modulations in the light spectrum of stars. Think of these rhythmic modulations as pulses, like the boom-boom bursts of energy that come from pulsars, or as the dots and dashes of Morse code. He said they would look like "two pulses of light, separated by very short times ... 10-12 seconds." These pulses, he says, don't have to come routinely, or very often at all. The key is that the pulses "be separated by the same time." His theory is that if highly advanced civilizations wanted to talk to us, sending these kinds of timed pulses would be the way to do it.
Borra says that since it's next to impossible to look for signals coming from an individual planet, sending the signal by changing a sun's spectrum would be an easily detectable way to send an interstellar calling card.
Armed with that theory, Borra and his team turned to data contained in the Sloan Digital Sky Survey, which has been mapping the universe for over a decade. They looked for any stars that exhibited evidence of these kinds of spectral shifts. What they found — or didn't find — surprised them. Borra says they found "the spectra we predicted in only 235 stars." That's right, of the 2.5 million stars they surveyed, they found just 235 that show this kind of change in their spectrum.
Now here's where things get a bit weird. It turns out that almost exclusively, the only kinds of stars in the universe that are shifting periodically are ones similar to our good old sun, which is a G2 Yellow Dwarf. Almost all the stars Borra identified are in this comfortable F through K range. Beyond that though, the stars don't have much in common. They are scattered all over the sky, so if it is indeed aliens, it's unlikely they know each other.
Borra himself isn't completely convinced that these shifts are an interstellar signal.
"After thorough analysis," he says, "we concluded that it is probably a real signal, but at this stage we must be very, very careful because it’s not certain."
He added that more research and better telescopes are needed to get to the real truth. "Right now," he says, "I’m basically waiting to see the reaction of the scientific community."
A second opinion
While we wait to get that reaction, VOA spoke with the scientists at SETI, The Search for Extraterrestrial Intelligence. This seemed right up their alley, since they think of themselves as an "exploratory science that seeks evidence of life in the universe by looking for some signature of its technology."
SETI Senior Astronomer Seth Shostak walked us through the science with a fair and critical eye. He mentioned the concept of bias in the report, something which Borra mentioned as well. One of the issues they both noted was that astronomers can't look at every star, so of course astronomers have tended to pick ones like our own. The sun, after all, is the only star we know for sure has given rise to life. That makes it more likely that the stars Borra found would be similar to ours.
Another point Shostak made is that in general, "if you look at millions of things, very slight problems with your instrumentation will show up in your data." So, it's not a surprise that out of the millions of stars surveyed, a few would show some unusual characteristics. But Shostak says that doesn't necessarily mean it's aliens. Borra and his team may have found "something unusual" out in space, he says. That "is the whole goal" of astronomy, but no reason to presume it's aliens. Unfortunately, he says, "Aliens are the first suspects in any crime."
Another, more practical point that Shostak made was that it seems a bit too coincidental that 200-plus stars, separated by tens, hundreds, or thousands of light years, would be broadcasting at the same time. "Not only is one of them doing it," he says, "but there are hundreds and they are more or less at the same level of intelligence?"
Finally, he says it seems an awfully big waste of energy, when you can send a similar signal into outer space just by turning on a radio. We've been sending radio waves into space for almost a century, but as to altering a star's spectrum? "It doesn’t sound like a great way to communicate," Shostak says. "...all of that is not to say it isn’t happening, but it does make you think that this is truly an extraordinary claim."
And it's important to note that Shostak isn't dismissing anything. This, he says, may be "incredibly important." But Shostak and Borra are both emphatic when they say that only time and research will tell.
So, if aliens are always the first suspect, this case is still wide open. But don't be discouraged, sky watchers. Shostak says he has plenty of bets with fellow astronomers that we'll find definitive proof that E.T. is out there in his lifetime. He calls it a three-way horse race. The first race is to find evidence of life in our solar system. That, he says, "is where the money is," with NASA looking at moons like Europa and Enceladus, as well as next door on Mars. The second race is to prove that there is life beyond our solar system. And finally, he says, there is the dream of finding Intelligent life out there.
Shostak is betting we see that in the next few decades.
Maybe Borra and his team have found it, maybe not, but everyone VOA has spoken to is emphatic in their belief that it's coming ... just stay tuned.