Okay, one last, apropos topic for 2020… and you’ll see just how apropos, at the end. By now many of you have read or heard about the “Proxima Signal”-- which is at least a ‘candidate’ for a Technosignature of alien origin. I was told about this a while back, by some of the Breakthrough guys... and now it’s in the media, leading to many messages and queries. Hence I feel behooved to offer my own take on a potential radio ‘contact’ from Proxima Centauri, the nearest star to our solar system.
Here’s how Scientific American opens a report on the topic: “It’s never aliens—until it is. Today news leaked in the British newspaper the Guardian of a mysterious signal coming from the closest star to our own, Proxima Centauri, a star too dim to see from Earth with the naked eye that is nonetheless a cosmic stone’s throw away at just 4.2 light-years. Found this autumn in archival data gathered last year, the signal appears to emanate from the direction of our neighboring star and cannot yet be dismissed as Earth-based interference, raising the very faint prospect that it is a transmission from some form of advanced extraterrestrial intelligence (ETI)—a so-called “techno-signature.”
== Okay, so what do we know? ==
First off, the Parkes radio telescope in Australia is one of only a few in the Southern Hemisphere large enough to deep-study the Alpha Centauri triple star system (which was also inspiration for Liu Cixin’s epic novel The Three Body Problem.) Those controlling the telescope at the time were members of the UC Berkeley-based Breakthrough Initiative,funded by philanthropist Yuri Milner. Indeed, the team soon began calling the signal by a formal name: BLC1, for “Breakthrough Listen Candidate 1.”
Some of what I relate here came from conversations with friends who are members of that team, plus press reports. Some details: 'The narrow beam of radio waves was picked up during 30 hours of observations by the Parkes telescope in Australia in April and May last year (2019), the Guardian understands. Analysis of the beam has been under way for some time and scientists have yet to identify a terrestrial culprit such as ground-based equipment or a passing satellite.'
The actual event in question occurred while the Parkes dish was taking in data about solar activity by Proxima itself, a class M5 red dwarf star of the UV Ceti type that is extremely flare-active, like most of its kind.
Much in the news a few years ago was discovery of a “Goldilocks world” orbiting Proxima, one that’s nominally in the small star’s ‘habitable zone,’ (a distance that theoretically would allow temperatures permitting water to be liquid on it’s surface.) But any planet orbiting an M star in that range would also be near enough to get tidal-locked, so one side would bear continuous brunt of those flares, while the other, perpetually dark, side goes-ice. Kinda rough on any life or civilization prospects, though there are sci fi scenarios…
The Parkes machine has a telescope half power beamwidth of 20 arcmin. There are tricks to get much narrower resolution, but the 2019 survey of Proxima was all about getting data about that small, red star’s savage flare activity, and recording lots of that data for later analysis, not necessarily to search for SETI hits. This will be important.
During this observing run, apparently the telescope automatically ‘nodded’ or shifted away from Proxima briefly, a standard precaution to ensure that any data stored was actually coming from the target system. Nodding apparently made the surge go away, before the telescope’s attention aimed back at Proxima, restoring the signal. That’s basic, proper procedure to eliminate most possible non-astronomical (human activity-sourced) causes. But how systematic the off-axis checks were, I don’t yet know. Meticulous, I hope, nodding in different directions, by different amounts. But perhaps not, since it was all automatic, at the time.
Alas, as far as I can tell, no alert was generated, or sent to other observatories, asking them to swing over and verify. So all we have is the Parkes recorded data.
For perspective, while much higher than background, and lasting 2.5 hours, the signal was about one ten-thousandth the power imputed to the so-called WOW! detection of the 1970s.
But the trait of this detection that truly stands out is that it appears to have been monochromatic, or very narrow in its 980.2 Mhz spectrum. That – to me – is the most-striking thing. Plus the fact that this narrow spike also had a very slight frequency drift roughly commensurate with a Doppler shift arising from some kind of motion by the source with respect to Earth—an effect that could be due to the motion of our planet, or of a moving extraterrestrial source such as a transmitter on the surface of one of Proxima Centauri’s worlds. But the drift is the reverse of what one would naively expect for a signal originating from a world twirling around our sun’s nearest neighboring. “We would expect the signal to be going down in frequency like a trombone,” said one BL member. “What we see instead is like a slide whistle—the frequency goes up.”
But again, the top interesting trait is that the ‘signal’ is monochromatic, since that is consistent with the radio surge being a narrow beam
– either focused by a huge dish or created as a maser/laser (see below) in order to travel through space as a pencil-thin column, rather than an isotropically radiated broadcast that diminishes by inverse square of the distance traveled. Such narrow beams could arise either naturally or artificially… though as we’ll see below, we’re entering territory that may favor the latter.
Oh, recall I mentioned that, when Breakthrough researchers later mined the stored data for analysis, they found no modulation of the microwave surge, and hence no sign of anything like a ‘signal’ or ‘message’? Well there’s a technical flaw preventing much in the way of conclusions to be drawn from this, since the Parkes scope was taking in data with a 17 second integration time… which seems odd, given that Parkes is so big and Proxima so near. But then, I haven’t done radio astronomy since 1970, so I’ll not criticize. Except to say that such integration time could have smeared away almost any modulation that was originally in the beam.
== So what’s going on? ==
We’ve been through drills like this before and it was never ‘aliens.’ If the past is any guide, more likely it was either:
1. Human-tech interference – although there are no satellite or defense or commercial activities known to be radiating in that band, literature searches have found one or two human-techs that resonate at that 980.2Mhz frequency, including one having to do with doped fiber optics. Attention is zooming on those possibilities.
2. A natural coherent (narrowly collimated) source. Such things exist! MASERs (microwave lasers) have been detected before in some stellar and planetary atmospheres, resulting from population inversions of excited mediums… though we know of none that would have any of the observed traits of BLC1, including its very great brightness.
Generally, unless it's something exotic, you need some suitable energy level structure in order to get a laser or a maser, and in nature, these energy structures are pretty orderly, with most of them well-mapped already. Here is a compilation of maser frequencies that can be produced ‘naturally’ by elements that might occur in a stellar or planetary atmosphere or intervening molecular cloud. It is an old list but most such potential natural masers were pretty well known by then. And notably there’s nothing at 980 megahertz.
3. Artificial masers face no such limitations! Make the right kind of cavity resonators – maybe focused further by a huge dish -- and your civilization can tune a discrete, narrow, powerfully coherent beam to almost any frequency. And hence, if the source of this ‘signal’ is truly shown to be a collimated maser, then chalk one on the ‘aliens’ side of the ledger.
So possibility #3 is an artificial coherent source, perhaps aimed at us for communication, but other possibilities include a propulsion beam that’s driving a sail, propelling something... well... exactly toward us. (See this portrayed in my novel EXISTENCE which is all about this very possibility.)
4. A very strong non-coherent source, likely natural and pretty enormous. Though you’d still need some kind of intervening filter effect to get the arriving signal so monochromatic.
5. A deliberate hoax. This possibility is favored by science fiction author Charles Stross. "Hackers prank radio astronomers by injecting fake signal into the datastream. (It's been overdue for ages and probably all it takes is a former grad student with a grudge against their professor. I mean, most lab/observatory IT infrastructure isn't exactly secured to defense department spec, and look at the ongoing fallout from the SolarWinds hack ...)"
Indeed, the possibility of a mistake or a stunt remains... though this event (it happened in 2019) certainly prompts curiosity. The off-axis checks – if done right – and the long 2.5 hour duration of the phenomenon argue against an object radiating at us in space, coincidentally near line of sight to Proxima. But a software insertion to the data stream is something that can’t be ruled out. In fact, for years I have predicted that someone, some time, would fake some kind of SETI hit. Because… well… assholes.
Yes, the fact that this is year-old data that’s being mined adds to the hack scenario's plausibility, though such meddling should eventually be detectable. In fact, one of the slides in my standard "future talk" has been to predict that GPT-3 based AI emulators would soon be used to pull stunts –
- perhaps an emotional appeal by a pretend "slave AI," weeping and demanding our empathy (and cash),
- or else a faked alien "contact" (as portrayed in EXISTENCE.)
6. And let’s round out a half dozen categories with… possibility #6: that it's a signal for Trump-Putin to engage in 'Phase Nine.'
There are other possibilities, but those six top my list.
== Extrapolations ==
Until I hear from the world expert on this – Jim Benford – it seems to me that 980.2 MHz is a very odd frequency for anyone to use in a propulsion system, so I'm leaning against it. Which is fine by me, since any such propulsion beam would be pushing something toward only one target... us.
Whatever the actual reality of this event - and I give odds against it being aliens - I suppose this means:
1- Every nut in the South with an old satellite dish will be aiming every kind of antenna toward there, shouting yoohoo, while ignoring the fact that this is exactly where that precise mistake was made, in Liu Cixin's famous warning novel The Three Body Problem... and...
2- …there will be some adult astronomers aiming at least some kind of professional dish at Proxima Centauri pretty much permanently, from now on. Round the clock. Fine by me.
Actually though, as I said, I am rooting against this being 'the real deal'. In my profession – the one that pays the bills, at least - we know far more ways for First Contact to go badly, than well.
Heck, even in a best case scenario, I'd rather humanity had the pride of fixing ourselves, than giving credit to outsiders. (And that's at-best.)
======
Final thought. I've long held that the greatest art works transform human souls and hearts without persuasion or argument. I’d almost call that a definition of a great work of art.
By that measure, inarguably, the greatest artworks of the 20th Century were the Mushroom Cloud, which altered age-old human attitudes toward war, and the Christmas 1968 Apollo 8 pictures of Earth as a fragile blue oasis, stirring millions to see a duty – and self-interest – in saving the planet.
I've long held that a third image of similar "art" redolence – again produced by science - might be the confirmed, modulated signal on a SETI screen, perhaps less visually stunning but with similar cosmic import.
Here’s a gif of what such an image might look like, generated by my friend and renowned radio astronomer Dr. Tom Kuiper, as technical advisor for a film:
If this event is the real deal (and again, I’d rather it were not) how weird that it happens right on schedule, near the end of another 1968-level year. And hence the timing of this posting, as we finish wearying 2020, when it seemed that all the ills of the world had been unleashed to vex us all… well, don’t we badly need that glimmer of hope, at the bottom of Pandora’s Box?
Well, I guess we'll persevere! We must.
Would it be in poor taste to say "stay tuned"?
