The Wow! Signal Deciphered. It Was Hydrogen All Along. (universetoday.com) 32
The Wow! signal, detected on August 15, 1977, was an intense radio transmission that appeared artificial and raised the possibility of extraterrestrial contact. However, recent research suggests it may have been caused by a natural astrophysical event involving a magnetar flare striking a hydrogen cloud. Universe Today reports: New research shows that the Wow! Signal has an entirely natural explanation. The research is "Arecibo Wow! I: An Astrophysical Explanation for the Wow! Signal." The lead author is Abel Mendez from the Planetary Habitability Laboratory at the University of Puerto Rico at Arecibo. It's available at the pre-print server arxiv.org. Arecibo Wow! is a new effort based on an archival study of data from the now-defunct Arecibo Radio Telescope from 2017 to 2020. The observations from Arecibo are similar to those from Big Ear but "are more sensitive, have better temporal resolution, and include polarization measurements," according to the authors. "Our latest observations, made between February and May 2020, have revealed similar narrowband signals near the hydrogen line, though less intense than the original Wow! Signal," said Mendez.
Arecibo detected signals similar to the Wow! signal but with some differences. They're far less intense and come from multiple locations. The authors say these signals are easily explained by an astrophysical phenomenon and that the original Wow! signal is, too. "We hypothesize that the Wow! Signal was caused by sudden brightening from stimulated emission of the hydrogen line due to a strong transient radiation source, such as a magnetar flare or a soft gamma repeater (SGR)," the researchers write. Those events are rare and rely on precise conditions and alignments. They can cause clouds of hydrogen to brighten considerably for seconds or even minutes.
The researchers say that what Big Ear saw in 1977 was the transient brightening of one of several H1 (neutral hydrogen) clouds in the telescope's line of sight. The 1977 signal was similar to what Arecibo saw in many respects. "The only difference between the signals observed in Arecibo and the Wow! Signal is their brightness. It is precisely the similarity between these spectra that suggests a mechanism for the origin of the mysterious signal," the authors write. These signals are rare because the spatial alignment between source, cloud, and observer is rare. The rarity of alignment explains why detections are so rare. The researchers were able to identify the clouds responsible for the signal but not the source. Their results suggest that the source is much more distant than the clouds that produce the hydrogen signal. "Given the detectability of the clouds as demonstrated in our data, this insight could enable precise location of the signal's origin and permit continuous monitoring for subsequent events," the researchers explain.
Arecibo detected signals similar to the Wow! signal but with some differences. They're far less intense and come from multiple locations. The authors say these signals are easily explained by an astrophysical phenomenon and that the original Wow! signal is, too. "We hypothesize that the Wow! Signal was caused by sudden brightening from stimulated emission of the hydrogen line due to a strong transient radiation source, such as a magnetar flare or a soft gamma repeater (SGR)," the researchers write. Those events are rare and rely on precise conditions and alignments. They can cause clouds of hydrogen to brighten considerably for seconds or even minutes.
The researchers say that what Big Ear saw in 1977 was the transient brightening of one of several H1 (neutral hydrogen) clouds in the telescope's line of sight. The 1977 signal was similar to what Arecibo saw in many respects. "The only difference between the signals observed in Arecibo and the Wow! Signal is their brightness. It is precisely the similarity between these spectra that suggests a mechanism for the origin of the mysterious signal," the authors write. These signals are rare because the spatial alignment between source, cloud, and observer is rare. The rarity of alignment explains why detections are so rare. The researchers were able to identify the clouds responsible for the signal but not the source. Their results suggest that the source is much more distant than the clouds that produce the hydrogen signal. "Given the detectability of the clouds as demonstrated in our data, this insight could enable precise location of the signal's origin and permit continuous monitoring for subsequent events," the researchers explain.
The MSM will report (Score:2)
Wow! Signal Caused by Extra Terrestrial Hydrogen!
Did an Alien civilization encode a message using a mysterious H1 gas cloud?
Scientists reveal rare spatial alignment coincided with detection of Alien Signal!
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The race for the sensationalist media to report it starts now:
Wow! Signal Caused by Extra Terrestrial Hydrogen!
Did an Alien civilization encode a message using a mysterious H1 gas cloud?
Scientists reveal rare spatial alignment coincided with detection of Alien Signal!
Nah. The media never hypes stories that debunk aliens. "Nevermind, it was just hydrogen" doesn't get ratings.
Now, finding a lump of dry clay on Mars and claiming it was ancient tube worms or something.... that stuff gets hype.
Why was ET contact ever a possibility? (Score:1)
So if the signal was actually caused by a magnetar flare exciting a hydrogen cloud -- an event involving such a colossal amount of energy that it could literally destroy a planet -- why was it ever considered a possibility that it was produced by an extra-terrestrial civilisation? Under what circumstances would it even be possible for a civilisation to concentrate energy at that sort of level? And, even supposing that it was possible, why would they radiate it out into empty space? If this was just a was
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The Drake equation indicates that there's an astronomically large number of alien civilisations out in the cosmos. In such a large collection, a randomly selected civilisation like the Earth's is simply going to be ranked near the middle on purely statistical grounds.
Just like an ant is ranked somewhere in the middle among the collection of multicellular living things: not too large and not too s
Re:Why was ET contact ever a possibility? (Score:5, Informative)
"The Drake equation indicates that there's an astronomically large number of alien civilisations out in the cosmos" - No, it doesn't. If you plug your assumptions into the Drake equations then it does, but that's just you assuming your conclusions. There is no evidence for any set of numbers going into the equation that produce "astronomically large" numbers of civilisations.
Going to your ant analogy, the problem is not about understanding, it's about fundamental limits. A magnetar is on the edge of collapsing into a black hole; that's a fundamental limit to how the universe works. A magnetar involves magnetic fields - on a stellar scale - that are strong enough to deform atoms into long thin rods. It is fundamentally not possible for a species that developed in normal planetary conditions to survive in a magnetar's environs because the nature of matter is different there. I'm not saying that a magnetar is the only way to form this kind of signal, but that that is the kind of energy concentration we are talking about. A species that developed in an ordinary life-supporting environment _cannot_ develop this kind of energy concentration because it is _necessarily_ inconsistent with their own survival, and to the degree that they might develop this sort of energy concentration at the sort of distance where they could survive it, it is not useful because it is necessarily so far away that the travel time to it is prohibitive.
I don't think you quite comprehend the power levels involved here. We have recorded outbursts from what we think are magnetar flares in our solar system. The first, detected in 1977, was intense enough to increase the radiation level in our solar system 2,000-fold at a distance of 163,000 light years; the radiation level outside of planetary magnetospheres is already enough to cause significant radiation sickness, implying that this event involved a power level sufficient to wipe out life in _the entire galaxy_ if they have no radiation protection in place and it was sustained over time.
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Because something that radiates a power level sufficient to wipe out life on the other side of the galaxy is necessarily so far away that it's not useful. Life would have to be at least thousands of light years away from it to survive, almost no matter what sort of shielding they have.
Of course, it's possible that faster-than-light travel is possible in some way we don't understand. As far as we can tell, it isn't.
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The only part I disagree with here is "so far away that it's not useful". I actually wrote a short story about this a long time ago, the premise of which was: a civilization sent out long-term mining probes in every direction in the galaxy. The probes were basically like Rama - they contained machinery to manufacture a crew when needed. So the idea was to send them in every direction, acquire a solar system, generate a crew from stored genetic info and onboard ingredients, begin mining resources and send th
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One of the fundamental aspects of our understanding of physics is that we extrapolate from our own local experience on Earth, both spatially (via symmetries and homogeneity assumptions) and historically (we extrapolate laws that we have discovered only). The latter extrapolation requires later corrections and paradigm shifts when we encounter phenomena which contradict our current understanding. The Schwar
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This is why I explained it in terms of very fundamental limits. An ant is unable to observe the earth at the sort of scale where nuclear weapons become comprehensible. We are able to observe the universe at the sort of scale where a magnetar becomes comprehensible. We are pretty certain that the speed of light is a fundamental limit. We know what effect extreme magnetic fields have on the nature of matter. This is not a "on no it's too big for us to think about" problem.
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Or, you know... maybe something went wrong and they all died.
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lol, yes.
As I've pointed out to another commenter, the sort of energy concentration we're talking about is fundamentally incompatible with life. A magnetar, which is what we now think produced this signal, produces a magnetic field so strong that atoms are deformed into rods 200 times longer than they are wide. Unless something evolved within that environment, there is no way for a lifeform to go from a normal environment to that environment. If they were going to evolve in it, they would have to get a m
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My money's on tardigrades. I have complete faith they'd be able to handle it. Somehow.
Re: Why was ET contact ever a possibility? (Score:2)
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Without knowing the answer, the context isn't there to know the magnitude of energy involved.
Assuming this is correct, the 'Wow' signal that required the massive amount of energy to manifest as it did would have been quieter than an overhead satellite with a mundane transmitter. They had no idea how far away the signal's origin was.
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So if the signal was actually caused by a magnetar flare exciting a hydrogen cloud -- an event involving such a colossal amount of energy that it could literally destroy a planet -- why was it ever considered a possibility that it was produced by an extra-terrestrial civilisation?
First, the signal itself didn't have "planet-destroying" energy. The (highly energetic) magnetar wasn't what was (hypothesized to have been) observed, it was the luminescence of the hydrogen cloud, which converted only a trivial portion of the magnetar flare energy to radio power.
And, second, we don't actually know the amount of energy. We knew the intensity of the signal here, but without knowing the distance and the directivity of the signal, we don't know the amount of power at the source. It could be a
It Was Hydrogen All Along. (Score:3)
And it would have gotten away with it, if it hadn't been for you meddling kids!
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...and it killed Sparky, too! [youtube.com]
Seems like I've heard this explanation elsewhere (Score:2)
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...All MIB jokes aside, this theory is comforting. The odd timing of the WOW event (occurring almost immediately after the effort to listen for ETs started) was always highly suspect.
Well, searching to ETs with radiotelescopes started with Project Ozma in 1960; the "WOW!" signal was 1977. So it wasn't really "almost immediately".
Wow! (Score:1)
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It took 47 years to determine that the signal was a nothingburger. How many billions were spent (wasted) in "researching" this phenomenon?
Very little. Not much money goes to looking at old data. The majority of SETI work has been privately funded since 1993, and is looking for new signals, not really re-analyzing old.
Not Saying (Score:2)
I'm not saying it was Hydrogen...
But it was Hydrogen.
IFO (Score:2)
I, for one, welcome our new Magnetar overlords.
And I'd like to remind them as a trusted Slashdot personality, I can be helpful in rounding up others to toil in their hydrogen fields...
ISR (Score:3)
In interstellar space, astronomical maser flares "Wow" YOU!
Nothing to see. Move along now. (Score:2)
It was just someone replaying Hitler's 1936 Olympic games opening address.
A million years from now, in a galaxy far away ... (Score:2)
an alien race's greatest minds will struggle to comprehend the first episode of I Love Lucy