A few weeks ago the journal Nature published two peer-reviewed reports put together by scientists at the Chime radio telescope project, situated in the Okanagan Valley in Canada’s British Columbia.
Chime – which stands for Canadian Hydrogen Intensity Mapping Experiment – maps the universe by using thousands of antennae to collect signals emanating from the night sky, and then uses the biggest processing system in the world to build up a picture of the galaxy… and beyond.
The reports published on 9 January caused a measure of excitement first in the academic world – the findings were simultaneously presented to the American Astronomical Society – and then in the wider media.
That’s because scientists at Chime had discovered a fast radio burster, or FRB. FRBs are essentially intense bursts of radio energy, which is not necessarily a strange phenomenon out there in the universe. But this time, something is different: these signals are repeating every couple of days.
What’s especially exciting is scientists don’t know what is causing these radio bursts. To most of us, this can mean only one thing: aliens.
To put it into context, these FRBs are coming from a long way away. Well beyond our galaxy, the Milky Way. Douglas Adams’ line from The Hitchhiker’s Guide to the Galaxy might well have been written especially to describe how far away they’re coming from: “I mean, you may think it’s a long way down the road to the chemist, but that’s just peanuts to space.”
The Andromeda galaxy is 2.5 million light years from us; the source of the FRBs detected by Chime is a thousand times more distant than that.
Before the project turned its hi-tech gaze on the heavens, there had been only one previously detected incident of a repeating FRB, and that was in 2012. “Knowing that there is another suggests that there could be more out there. And with more repeaters and more sources available for study, we may be able to understand these cosmic puzzles – where they’re from and what causes them,” says Ingrid Stairs, a member of the Chime team and an astrophysicist at UBC.
The fact that scientists don’t know what is generating the FRBs raises the spectre that they are actually the work of some far-flung civilisation.
The Seti (search for extraterrestrial intelligence) Institute in California is dedicated to finding evidence of alien life. Senior astronomer Seth Shostak wrote on the Seti website that FRBs in and of themselves weren’t necessarily cause for cracking open the champagne and laying out the interstellar welcome mat.
“It’s lore among astronomy grad students that cosmic phenomena are either singular – in other words, there’s only one in the universe – or they’re very common,” Shostak writes. “For example, some folks have argued that Earth might be unique. Maybe there’s only one such bio-friendly world in our galaxy, and we live on it. But a more frequently heard opinion is that, among the trillion planets of the Milky Way, there could be many billions that have spawned life.
“When, a few years ago, only a handful of FRBs were known, it was unclear whether they were rare or otherwise. Now that more than 60 have been detected, researchers can safely say that there are probably thousands of these things going off every day. They are as ubiquitous as indoor plumbing.”
The exciting bit is that the FRB discovered by Chime is repeating. Shostak explains: “There’s a short flash of radio energy – quicker than an eye blink – and then, maybe two days later, it flashes again.
“The repetition tells you something about the cause of these radio flashes. Obviously, you can’t expect that colliding black holes or neutron stars are going to return to their corners and collide again a few days later. Whatever is responsible for this series of bursts has to be an ongoing phenomenon.
“In addition, the phenomenon has to be tremendously energetic. The radio flashes come from billions of light years away.
It’s lore among astronomy grad students that cosmic phenomena are either singular – in other words, there’s only one in the universe – or they’re very common
Seth Shostak, senior astronomer at the Seti Institute
“Clearly, something in that galaxy can muster sufficient energy to produce a signal detectable here on Earth. And it can come up with that energy every few days or so.”
Taken on its own, the FRB discovery might not have caused as much general interest as it did. But the news came alongside another announcement, and that concerned ‘Oumuamua.
‘Oumuamua is actually the Hawaiian word for scout, or messenger, but it has that lovely science fictional ring to it. A common trope of science fiction is the idea of the Big Dumb Object – a huge, unknowable, alien structure that appears in our skies or on Earth, a mute testimony to the existence of extraterrestrial life. Think the monoliths from Arthur C Clarke’s 2001: A Space Odyssey or his novel Rendezvous with Rama, in which an enigmatic cylindrical object glides into our solar system.
Clarke, who died in 2008, would have loved ‘Oumuamua. The name was coined by scientists at the University of Hawaii when they spotted the strange object passing through our system, not unlike Rama, in October 2017.
‘Oumuamua was an asteroid – or something similar – an elongated lump of rock anything up to a kilometre long, and red in colour. It was notable in astronomical terms because it was the first time an object from outside our solar system was detected to be just passing through.
There were the usual internet theories about it being something to do with aliens, of course, but they weren’t taken very seriously. Until October last year, when the chair of Harvard’s astronomy unit, Avi Loeb, went on the record to say, actually, this could be aliens, you know.
Basing his statements on the observations that ‘Oumuamua appeared to accelerate at certain points during its passage past us, Loeb told German news magazine Der Spiegel that it “may be a fully operational probe sent intentionally to Earth’s vicinity by an alien civilisation”. He added: “If these beings are peaceful, we could learn a lot from them.”
Scientists are generally a little wary about tossing around assertions that not only does alien life exist, but that it has progressed to the point that it can disguise its spaceships as asteroids and send them spinning through the galaxy.
Even Seti, which wears its heart on its sleeve when it comes to its mission to find alien life, has poured cold water on the repeating FRBs being of alien origin. Seth Shostak writes: “Aliens are frequently given the credit for causing new celestial phenomena. A half century ago, Soviet scientists suspected that quasars were actually signals broadcast by highly advanced societies far, far away. In the 1960s, British radio astronomers temporarily referred to pulsars as little green men.
“But you can safely bet that aliens are not the cause of FRBs. Why? The bursters are seen all over the sky, that’s why. The same sort of signal is coming from galaxies that are generally separated by billions of light years. So how could aliens organise so much of the universe to engage in broadcasting the same sort of signal? There’s hardly been enough time since the Big Bang to coordinate such widespread teamwork, even if you can think of a reason for it!”
This week The New Yorker magazine interviewed Loeb. He could reasonably have been expected to backtrack a little on his pronouncements from October regarding ‘Oumuamua. But not a bit of it. He went further, suggesting that ‘Oumuamua was some kind of solar-powered sail to account for its change in speeds, which you would not expect to see from a dead object simply drifting through space.
Not believing in aliens is akin to believing the world is flat, vaccines cause autism, and the world was created in seven days. No sensible person believes we are alone in the universe
Loeb told The New Yorker: “The only thing that came to my mind is that maybe the light from the sun, as it bounces off its surface, gives it an extra push. It’s just like a wind bouncing off a sail on a sailboat. So we checked that and found that you need the thickness of the object to be less than a millimetre in order for that to work. If it is indeed less than a millimetre thick, if it is pushed by the sunlight, then it is maybe a light sail, and I could not think of any natural process that would make a light sail. It is much more likely that it is being made by artificial means, by a technological civilisation.”
But Loeb sounded a cautionary note for any ET fans out there. The civilisation that sent out ‘Oumuamua – much in the same way we sent out the Voyager probes – could be long extinct, given the distances it might have travelled.
But still, here’s a respected Harvard scientist saying that he believes in aliens: “I do not view the possibility of a technological civilisation as speculative, for two reasons. The first is that we exist. And the second is that at least a quarter of the stars in the Milky Way galaxy have a planet like Earth, with surface conditions that are very similar to Earth, and the chemistry of life as we know it could develop. If you roll the dice so many times, and there are tens of billions of stars in the Milky Way, it is quite likely we are not alone.”
It’s the sort of thing people have been saying for years, but to hear it from such an august personage adds weight to the fact that belief in aliens is no longer confined to the tinfoil hat brigade.
I punted out the question of whether aliens exist on social media. Perhaps it’s the sort of people who follow me, but nobody came out and said they didn’t believe in the existence of aliens. One reply on Twitter read: “Not believing in aliens is akin to believing the world is flat, vaccines cause autism, and the world was created in seven days. No sensible person believes we are alone in the universe.”
Thinking exactly that seems to be ridiculed as much as the idea that there were aliens out there used to be not so long ago. One commenter called the idea “narcissistic”; another said, “It would be bizarre to think we are the only life in the universe. Equally bizarre to believe that the universe is small enough for us ever to have the chance of meeting other life.”
That last comment is perhaps indicative of the idea that while life might exist on other planets, we might never be able to get there, or vice versa.
“Maybe not this year, but in the next five years,” asserts author Rowan Coleman when I ask on Facebook if 2019 is going to be a big year for aliens. “Nasa are sending probes to Europa and other moons with frozen water on them. There’s a lot of frozen water which is sometimes fluid on mars. Given that microbiotic life can survive on Earth in both freezing and boiling conditions, and in the vacuum of space, it seems pretty obvious we’d find this kind of life within within our solar system.”
David Darby adds: “My prediction is that everywhere you find liquid water you will find life – it has been shown to be the case on Earth no matter how extreme the environment. We may only discover microscopic unicellular life as this is the only life that can be expected within our universe. Interstellar travel times would mean that any galactic empire would probably remain undiscovered as our technology won’t get us there. Our planet has been here long enough for them to visit us if they had the technology or inclination. The fact that they haven’t would probably mean that interstellar travel is a technological problem with no solution. The one thing we can be sure of is that ‘the truth is out there’…”
The idea of discovering microscopic life is one that has gained much more traction in recent years, and Coleman’s point about life on Earth surviving in extreme conditions is one that comedian Ben Miller made heavily in his recent book The Aliens Are Coming!
Miller – who studied at Cambridge for a PhD in solid state physics – is firmly of the belief that life is out there, but that we’re likely to find microbes before the silver spaceships come flying.
He tells me about microbes that exist in hot springs in Yellowstone National Park in temperatures of 90C, about 30 degrees above what they should be able to withstand. If they can survive in those conditions here on Earth, why not on other planets?
Are alien civilisations sending out repeating radio signals and solar-powered probes to investigate life on Earth? What used to be a belief that was cause for ridicule now seems to be much more widely accepted as not just true, but inevitable.
Will we find life – whether microscopic bug or galactic empire – in 2019? It feels, on recent evidence, that if we’re going to make contact, then this year, or the next, or maybe the next after that, seems increasingly likely. Keep watching the skies…
We’ll tell you what’s true. You can form your own view.