It’s September 2018, and a brand-new radio telescope is in its first week of scanning distant corners of the universe in the hunt for unusual signals. Researchers have already discovered some telltale signs of mysterious radio waves known as fast radio bursts. And one of those has an extremely rare property: it repeats.
The enigmatic radio signals have been detected by the Canadian Hydrogen Intensity Mapping Experiment (CHIME) telescope. Sat about three miles from British Columbia’s Okanagan Falls, The Canadian Dominion Radio Astrophysical Observatory hosts the CHIME telescope. The Observatory is also home to an array of other exploratory devices, including four orthodox radio telescopes.
Meanwhile, the CHIME project got going back in 2013 when scientists and engineers at the Dominion Observatory built the CHIME Pathfinder. This was basically a smaller version of the final machine. It had two 120-foot long semi-cylindrical strictures. The final CHIME telescope has four of those, sometimes described as being akin to a snowboarding half-pipe, and each is nearly 330 feet in length.
CHIME has an innovative design which allows it to operate without moving parts. Its original purpose was to monitor the presence of one single element across much of the observable universe, hydrogen. The digital signal it collects allows the creation of three-dimensional charts of hydrogen density. This information can in turn be used to calculate the speed at which the universe is expanding.
However, as it collects data about hydrogen, it can also detect the fast radio bursts that we heard about earlier. Indeed, these fascinating manifestations have now been observed by CHIME and other telescopes some 60 times. The first time such a radio burst was discovered was in 2007. That burst actually happened in 2001, but was only noticed later by a student called David Narkevic as he analyzed historic data.
But what exactly are these fast radio bursts? The truth is that scientists are still puzzling over the answer to this question. The radio signals certainly can come from extreme distances. For example, one of the 13 fast radio bursts observed by CHIME came from some 1.5 billion light years away. And don’t forget that a single light year, the distance light travels in 365.25 days, is 5.88 trillion miles.
And that particular signal, known as FRB 180814, was an especially unusual one among the 60 so far detected by the CHIME telescope. It was a repeating signal as opposed to the other 58 signals that were only observed once. And it was only the second such signal ever detected, with the first one having been observed six years previously.
The first repeating fast radio burst, FRB 121102, was detected in 2012 by the Arecibo radio telescope in Puerto Rico. This one came from the region of the constellation Auriga, “The Chariot,” some three billion light years distant from our planet. So scientists now have evidence of two repeating fast radio bursts.
But researchers are no closer to understanding their origin, although there are various tentative theories. Speaking to the BBC in January 2019, University of British Columbia astrophysicist Ingrid Stairs commented on the significance of the discovery of a second repeating fast radio burst. She said, “Knowing that there is another suggests that there could be more out there.”
“And with more repeaters and more sources available for study,” Stairs continued, “we may be able to understand these cosmic puzzles – where they’re from and what causes them.” One idea mooted by some, almost inevitably, is that these radio signals might be signs of intelligent life elsewhere in the universe.
Meanwhile, alien intelligence isn’t exactly the favored explanation of most serious scientists. Though it’s a theory that has undeniably intriguing implications. Of course, the search for extraterrestrial life, particularly intelligent life, has been the stuff of fiction as much as of hard science for generations. And it’s a commonly heard question: are we alone in the universe?
The hunt for extraterrestrial intelligence dates back to at least 1896. Back then Nikola Tesla, an American of Serbian heritage, came up with the idea of contacting aliens on Mars via radio. And yes, that’s the man that Elon Musk named his electric automobiles after. For his part, Tesla had invented a radio system without wires.
During experiments Tesla conducted with his new equipment at his Colorado Springs laboratory, he believed he had picked up signals from Mars. However, reviewing Tesla’s work, later researchers were not so sure. Italian inventor Guglielmo Marconi was conducting radio experiments in Europe and some thought those may have been the signals Tesla picked up.
Nevertheless, various eminent scientists, including Marconi himself, believed that there was a genuine possibility that Earth could communicate with intelligent life on Mars via radio transmissions. And the inventor went even further, claiming that he too had detected radio signals from the Red Planet. Of course, we can now be pretty certain that Mars harbors no intelligent life.
Now, we may well scoff at the naivety of those early searchers for alien life. That’s easy enough to do with the advantage of hindsight and the knowledge we now have about the planets in our Solar System. But in the early part of the 20th century, the idea of intelligence on our neighboring planets seems to have gripped the public’s imagination.
Indeed, this interest in extraterrestrials and the stars was so strong that in 1924 a National Radio Silence Day was declared in the U.S. A 36-hour period in August was chosen for this event because that was when Mars was due to be closer to Earth than it had been for 100 years previously and would be for 80 years into the future.
A renowned American astronomer of the day, David Peck Todd, believed that this moment when the two planets were close together might well be the time when beings on Mars would attempt to make contact with Earthlings. Meanwhile, radio audiences were implored to turn their sets off for five minutes every hour during the national silence so that signals from Mars could be detected.
In an experiment led by Todd with the co-operation Admiral Edward W. Eberle, the U.S. Navy’s operational commander, a special radio receiver was put in place. The equipment was lifted by a large balloon to a height of just short of two miles to give it the best chance of receiving signals from Mars.
And the U.S. Army got in on the act as well. Its chief code-breaker, William F. Friedman, was on hand to decipher any messages that should come through. Sadly, despite these elaborate preparations and the recruiting of the American public in this early example of citizen science, no signals from Mars were detected.
After these early 20th-century attempts at making contact with aliens, the next major event came in 1960 with Project Ozma. Frank Drake, an astronomer at Cornell University in Ithaca, New York, was the first to perform a modern search for extraterrestrial intelligence (SETI) operation. And for his part, the scientist used a powerful radio telescope at Green Bank, West Virginia, for his research.
Drake used the Green Bank telescope to closely examine two stars, Epsilon Eridani and Tau Ceti. It was certainly more scientifically rigorous than Todd’s 1924 attempt to find evidence of alien life. But Drake’s experiment ended with the same result: it drew a complete blank. Undeterred, though, Drake secured funding from NASA in 1971 and developed his ideas on how to search for alien life.
Drake and his colleagues proposed a huge radio telescope network dubbed Project Cyclops. Equipped with 1,500 dishes, the estimated cost of the program was put at $10 billion. And perhaps unsurprisingly, Drake’s ambitious project was never built. However, it did form the foundations of much of the SETI work that was to follow in the years to come.
A momentous event in the SETI world came in 1977. That year, a volunteer at the Ohio State SETI project saw a powerful and unusual signal in the radio telescope data. Grabbing a pen, he drew a circle around the signal on the paper printout and appended it with the enthusiastic exclamation “Wow!”
Naturally enough, this single piece of data became known as the Wow! signal. Furthermore, many believed this was the strongest evidence yet that somebody or something out there was transmitting signals. But since no similar signal has ever been detected again, the importance of this moment seems to have been diluted as the years have rolled by.
Meanwhile, SETI projects continued through the 1980s and 1990s. And these ones involved ever more sophisticated efforts at scanning the skies for possible signals from extraterrestrial beings. But nothing that could be definitively described as a message from an alien intelligence came to light. Then on into the 21st century, various projects came and went, often concluding as funds dried up.
Elsewhere, other current projects include the Breakthrough Listen initiative. This project is headquartered at the Berkeley SETI Research Center and draws on data from the Australian Parkes Observatory and the U.S. Green Bank Observatory. Launched in 2015, this is a £100-million, ten-year program which analyzes many thousands of hours of radio telescope data each year. And veteran alien searcher Frank Drake is working on the program.
There are also a variety of community based SETI research projects which allow the general public to get involved in the search for extraterrestrial intelligence using their own home computers. And perhaps the most notable of those is the [email protected] program. This initiative is run by the University of California’s Space Sciences Laboratory at Berkeley and launched in 1999.
Members of the public can get involved in the [email protected] project by downloading the requisite software, the Berkeley Open Infrastructure for Network Computing. This gives the pleasingly whimsical acronym of BOINC. And once installed, the software uses the processor power of computers when they are on downtime to process data from radio telescopes.
Sadly, the [email protected] project has had no more success in identifying concrete evidence of alien communications than any other initiative. But that brings us back to the signal that we heard about at the beginning of this piece. You’ll remember that it was detected by CHIME, the Canadian Hydrogen Intensity Mapping Experiment.
And early in its operation, the CHIME telescope had detected something that was highly unusual: a repeating fast radio burst. And fast radio bursts are rare enough in themselves. Indeed, only around 60 have ever been detected, 13 of those by CHIME. But this burst, dubbed FRB 180814, was a repeating one and only the second ever picked up.
So could this rarely seen fast radio burst be an attempt by aliens to communicate with other sentient beings across the universe? The scientists were able to say that the signal came from 1.5 billion light years away. But was this a long-distance message sent by an extraterrestrial intelligence? Well, some people certainly thought it might be.
Notable among those who think alien intelligence could be responsible for signal FRB 180814 is a professor from the Harvard-Smithsonian Center for Astrophysics, Avi Loeb. In 2017 he and one of his co-workers at the Harvard-Smithsonian Center, Manasvi Lingam, came up with an interesting theory about the possible origin of fast radio bursts.
Lingam and Loeb theorized that fast radio bursts could be signals that had leaked from extraterrestrial transmitting equipment. The equipment could be enormous, the size of a planet, they believed. The apparatus was probably not designed as a transmission device they said. And what the Harvard-Smithsonian Center duo believed the true purpose of the equipment might be is intriguing to say the least.
The two scientists posited that the equipment might actually be a massive power generation plant designed to drive gigantic spaceships. These ships would likely be driven by gargantuan light sails. And these sails would reflect radio waves on to reflective surfaces, giving the necessary thrust to propel the ships into space.
According to this, let’s be honest, outlandish theory, the fast radio bursts detected by CHIME and others were from a spillage of these powerful radio beams used to drive enormous spaceships. So the signals detected by CHIME were produced by activities by intelligent extraterrestrials. For his part, Loeb expanded on his theory in an interview with The Guardian in January 2019.
“Fast radio bursts are exceedingly bright, given their short duration and origin at great distances. And we haven’t identified a possible natural source with any confidence,” Professor Loeb told The Guardian. He added, “An artificial origin is worth contemplating and checking. Science isn’t a matter of belief, it’s a matter of evidence. Deciding what’s likely ahead of time limits the possibilities. It’s worth putting ideas out there and letting the data be the judge.”
But as you’d expect, there are other theories out there about what these fast radio bursts, including the repeating ones, actually are. The scientists working with the CHIME telescope at the Dominion Radio Astrophysical Observatory have their own ideas. Their thinking is colored by the fact that most of the 13 fast radio bursts they’ve detected a display called “scattering.”
The CHIME scientists believe that this scattering is evidence that the radio waves probably originate from high-energy astrophysical objects. These are likely to be present in parts of the universe with unusual properties. Speaking to the Phys.org website in January 2019, one of CHIME’s scientists, University of Toronto astronomer Cherry Ng elaborated.
Ng described what the scattering phenomenon might indicate about the radio burst origins. She said, “That could mean in some sort of dense clump like a supernova remnant. Or near the central black hole in a galaxy. But it has to be in some special place to give us all the scattering that we see.” So these unusual radio waves might not be from an alien intelligence, but they were likely to be from a decidedly offbeat corner of the universe.
In fact, scientists also believe that although only 60 fast repeating radio bursts have been observed, there are likely to be many more of them reaching Earth, perhaps up to 1,000 per day. But the question remains, will extraterrestrial beings ever contact us? Indeed, there are an estimated 100 billion stars in our galaxy, the Milky Way, many with planets orbiting them. And there are as many as 200 billion galaxies in the universe. So there might be somebody out there.