A recent study conducted by the American Astronomical Society, published in the Astrophysical Journal, has confirmed that scientists have received a total of 17 fast radio bursts (FRBs) from a single source outside of the Milky Way galaxy since 2011. Unfortunately, because of the immense distance between Earth-based radio satellites and the source, little more can be confirmed about just what, exactly, is transmitting.
By pointing an array of radio telescopes at a specific point in the constellation Auriga, scientists have received multiple bursts of radio waves, significantly greater in energy expended than the background radio interference reverberating through the universe, which scientists believe is a leftover from the Big Bang. These radio bursts, first received in 2011 but not confirmed to be repeating until earlier this year, have each been at least three times more powerful than anything scientists expected to pick up.
Radio waves of this sort could theoretically be produced by naturally occurring phenomena like a supernova created by a star exploding, but because the bursts are repeating, scientists have ruled out such a possibility. In effect, the same star would have to explode repeatedly, from the same location, and at regular intervals in order to transmit such a repeating wave of radio signals.
“Our discovery of repeating bursts from FRB 121102 shows that for at least one source, the origin of the bursts cannot be cataclysmic, and further, must be able to repeat on short [less than one minute] timescales,” the authors wrote in a peer-reviewed paper published on December 16th.
Technological limitations prevent scientists from determining the specific location from which the signals originated, or even the exact distance they’ve traveled in order to reach our detection instruments on Earth, but based on the magnitude of the signal, they have been able to confirm that it is “extragalactic,” or based outside of our own galaxy, the Milky Way.
Fast radio bursts are extremely short-lived, lasting only a few milliseconds each, and are, at least currently, also extremely rare. Less than 20 fast radio bursts have ever been detected elsewhere in the universe, and no other burst has ever repeated. These bursts detected from the constellation Auriga have repeated an unprecedented 17 confirmed times, leaving scientists puzzled as to what could be producing the signal.
Scientists believe the signals are coming from a region surrounding a young neutron star inside a dense cloud of space debris, but cannot confirm that, nor can they offer a suitable natural explanation for the signal. However, that doesn’t necessarily mean they’ve located E.T., as there are still many types of space-borne phenomena that we don’t understand. Some theories, however, do suggest that this could be the first verified and repeatable evidence of intelligent life elsewhere in the universe.
The Drake Equation, proposed by noted radio astronomer Frank Drake in 1961, uses algebra to associate known quantities in our realm of the galaxy (such as the rate of star formations, the number of stars that have planets orbiting them, and the number of planets within those solar systems that orbit within the star’s “habitable zone”) to establish a prediction for how many intelligent species there may be in our galaxy. Although the equation has been modified and debated thanks to modern discoveries of exoplanets with far greater frequency than previously predicted, Drake theorized that there were at least 12,000 intelligent species within just our own galaxy.
Even with so much potential, the chances we would ever discover such a species remains tiny, as just our own galaxy is so expansive it would effectively be like searching for a needle in a haystack the size of the Pacific Ocean, not to mention the likelihood that any such species (including our own) would go extinct before ever reaching the technological level required for interstellar travel or communications. Even so, many scientists have called the equation into question, asking why, if there are so many intelligent life forms out there, we have yet to find any evidence to support it.
The response from many within the scientific community has been that, even if an alien race were advanced enough to travel the stars, that doesn’t mean they would also develop, or choose to use, radio communications, as radio signals travel at the speed of light, which would be fairly useless when communicating across light years of space. A radio signal from Earth, for instance, would take up to 100,000 years to cross our galaxy, making communication with a ship at that distance effectively impossible using radio waves.
So the source of these signals likely isn’t a means of communicating internally for some space-faring civilization, but it could be a beacon intended to get the attention of other races in the universe that, like us, have the technology required to receive signals transmitted over wavelengths of light. It’s also possible that the signals could be produced as an unintentional byproduct of a technology we are unaware of, such as a means of propulsion. Similarly possible is the theory that these signals are produced by an as-yet undiscovered natural phenomenon.
This discovery echoes excitement within the scientific community started in 2015, when researchers discovered a star approximately 1,500 light years away that was dimming “oddly and dramatically” at regular intervals. Some scientists at the time postulated that it could be the result of a Dyson sphere, which is a theoretical structure used to harness the power of a star. The dimming of the star is far too significant to be caused by a planet; at times whatever is orbiting the star reduces light transmitted by as much as 22 percent, while other times its light is almost completely visible.
“I’d say we have no good explanation right now for what’s going on with Tabby’s star,” Jason Wright, an astronomer at Pennsylvania State University, said about the dimming star last October. The star has also dimmed overall over the span of recorded history, something current scientific models of a star’s lifespan are unable to account for. Once again, although theories range from a vast array of space-based solar panels to a space station so enormous it could block out its own sun, many scientists still believe there may be a natural explanation for the occurrence, just one we are not yet aware of.
As our technology continues to advance the horizon of what we are able to observe and study, chances are good that we will continue to run into these sorts of mysteries—some of which may be explained away through newly discovered natural occurrences, and others that may prove tougher to dismiss. Scientific consensus among astronomers has shifted over the past 30 years, leaving most in the community nearly certain that life exists elsewhere in our universe. These recent discoveries may silence those who challenge the Drake equation by asking, “If they exist, why haven’t we found them?” because we may have already. The question is, if we find them, should we attempt to communicate?
Steven Hawking, possibly the most famous physicist of our generation, doesn’t think so. He believes there is life elsewhere in our universe, and that some is likely significantly more advanced than our own. With that in mind, he predicted we would receive radio transmissions from some such civilization one day (perhaps in the form of FRBs), but isn’t sure we should respond when, and if, we do.
“We should be wary of answering back,” he said in a video for CuriosityStream. “Meeting an advanced civilization could be like Native Americans encountering Columbus. That didn’t turn out so well.”
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