Phosphine detected in the atmosphere of Venus – an indicator of possible life?
ras.ac.uk
ras.ac.uk
Press conference live stream: https://www.youtube.com/watch?v=5IIj3e5BFp0
To the best of the reasearchers' knowledge: All known pathways to produce phosphane couldn't explain the observation (they were talking several orders of magnitude off). Abiotic 'exotic' chemistry is still an option (ie the 'unknown unknown' hasn't been ruled out).
It's impossible to rule out an "unknown unknown" by definition, because if you did then it wouldn't be "unknown" anymore.
That's K-K, not U-U.
There are unknown biotic pathways known to exist (from the press conference, biotic phosphane production on earth apparently still has some large question marks attached?).
There might be unknown abiotic pathways ('unknown unknowns'). In principle, there could be some clever way to rule them out based on the constraints of the Venusian environment.
A sample of aliens can help leapfrog our understanding of biology, just like the study of terrestrial bacteria allowed us to precisely edit genes. Really interesting things happen biologically in extreme conditions.
(This estimate assumes that tidal forces are proportional to 1/R^3 and that the orbital radius of Venus is 73% of Earth's)
They were pretty clear in stating up front they have not ruled out abiotic processes, and are not declaring that they have discovered life. They state based on the known conditions of Venus and known chemical pathways to phosphine, and what is known about phosphine as a bio-marker, that life is a distinct possibility.
Through further research either we'll learn something new about Venus, phosphine production (which could improve our understanding of its relevance as a biomarker in the universe), or confirm some form of biological process.
The live stream that I can see is at https://www.youtube.com/watch?v=y1u-jlf_Olo
- Phosphene found
- We don't know how it could naturally occur in Venus without life
- We don't know any life that could survive in so that acidic environment (toughest microbes in earth survive 5%, Venus's atmosphere has 90%)
- We need to send a probe to test
/s
If the probe was built to withstand higher temperatures it could descend towards the end of the mission and do more work at lower altitudes. It's unlikely there would be a surface mission because of the weight involved with keeping electronics working at 464°C/867°F.
An initial probe to determine if life is actually there is going to be tough, but maybe doable. But the real jazz is in sample return.
You'd want those little critters in human hands so you can do experiments and really study them. That is a very tall order, depending on the conditions that these bugs may be in. You gotta keep them alive for the return trip, with only basic ideas of their life cycle and proclivities. An aerobrake, that's hard, but doable. But if the things only live in a thick part of the atmosphere, then you gotta get back into orbit while hanging off a balloon. Or something like that. Not easy.
Even on Mars, with less gravity and less atmosphere and cold temperatures, we've never done sample return. It's really really hard to do. Venus ups the hard parts of Mars even more so.
But Life (if it's there) is just too seductive. It'd be a space race like no other, NASA, ESA, Russia, China, all vying for viable sample return. God, that may be a really cool thing to see. It would totally change how we think of ourselves in the solar system, if not the universe.
[0] Venus is tidally locked to the Sun (kinda), year/day is the same time length.
If there ever were a premise for one in our time it would be fusion, or carbon extraction... but this seems to be either woefully underfunded or in the hands of private enterprise.
Given the way the starlink was heralded by the media, the time of nations challenging each other to technological conquests is now commandeered by the venture capitalists.
These are not research fields with a definite, discrete goal condition. They are ongoing research fields.
The discovery of extra-terrestrial life is a huge, discrete goal condition. Everyone will remember which team/country first discovers and demonstrates such life. Few will remember who confirmed it (i.e. who came second).
It's not like we're short on Nobel Prizes here.
https://www.youtube.com/watch?v=y1u-jlf_Olo
A caller asked Professor Sara Seager about sending a probe with a balloon, and she likes that idea, and said that was what the Vega program previously did:
https://en.wikipedia.org/wiki/Vega_program
>The Vega program (Cyrillic: ВеГа) was a series of Venus missions that also took advantage of the appearance of comet 1P/Halley in 1986. Vega 1 and Vega 2 were uncrewed spacecraft launched in a cooperative effort among the Soviet Union (who also provided the spacecraft and launch vehicle) and Austria, Bulgaria, France, Hungary, the German Democratic Republic, Poland, Czechoslovakia, and the Federal Republic of Germany in December 1984. They had a two-part mission to investigate Venus and also flyby Halley's Comet.
A Russian caller mentioned a proposed Russian space mission to Venus called Venera-D:
https://en.wikipedia.org/wiki/Venera-D
>Venera-D (Russian: Венера-Д, pronounced [vʲɪˈnʲɛrə ˈdɛ]) is a proposed Russian space mission to Venus that would include an orbiter and a lander to be launched in 2026 or 2031. The orbiter's prime objective is to perform observations with the use of a radar. The lander, based on the Venera design, would be capable of operating for a long duration (≈3 h) on the planet's surface. The "D" in Venera-D stands for "dolgozhivushaya," which means "long lasting" in Russian.
Either a) it's the same DNA - in which case some basic panspermia - some material bounced between Venus and Earth, in one or both directions, some billions of years ago, or b) it is demonstrably not the same structure as life on this planet, in which case statisticians get to have a field day.
You would have considerable choice; it would be quite obvious whether they'd been on a separate evolutionary trajectory for billions of years or not. That's still the boring outcome, though; not related to us at all would be far more interesting.
Very, very unlikely outcome.
However, happening on two adjacent planets would really affect our estimations of the likelihood of abiogenesis.
Life could have arisen on Earth much later than it did and we could still have been around to see it (or if not us, something like us) so the anthropic principle doesn't apply here. The fact that it arose so early is meaningful.
I would assume it is DNA-based life. It would be a major surprise if it would be RNA-based life or something not resembling our tree of life.
In any case it makes it much less interesting, as it implies same origin.
Implies but does not prove, I should add, of course.
“Match” means “match”. Not “similar structure and behavior”. If it is the same DNA then the only compelling explanation is that it is from the same origin.
How likely is it that alien life would also use DNA?
So if something is an exact match it is evident that they came from the same time and place (within some reasonable window). The origin would implicitly be Earth in the 1960s.
DNA and RNA: Perhaps they are inevitable, and any lifeforms have the same molecules and bases. Perhaps some lifeform can use only the methylated versions? Is ribose inevitable? Is 3 bases per codon inevitable? But I think there is a chance for inevitability.
The list of amino acids is somewhat random. We use 20, Some bacteria use a 1 or 2 more. And we can transform in place the amino acid inside a protein into another amino acid. I expect a similar list of 20+-5 amino acids. A perfect coincidence would be too hard, but it is not even true for terrestrial life.
The most interesting part is the Genetic Code https://en.wikipedia.org/wiki/Genetic_code that translate the 4^3=64 combinations of bases in the DNA to the 20 amino acids. As far as we know it is random. It has some internal structure, for example the code is mostly like 16 blocks to encode 15 amino acids and a stop signal, and a few tweaks here and there to break some block to encode the other 5 amino acids. But as far as we know there are no reasons to choose each block as us.
Some bacteria use versions with small tweaks, with one or two changes, so we know it if possible to change it, but very difficult to make a total rewrite.
If the life out there use the same Genetic Code (with a few tweaks) it is almost sure it is related to us.
https://www.sciencedirect.com/science/article/abs/pii/S00225...
Now, I'm not an expert or even an advanced layperson in this area, so I won't attempt to speak to the validity of the idea. I merely found the argument interesting at the time.
First they propose a genetic code that is totally unrelated to the current one. It can be perfectly the table of a totally different lifeform. The transition they propose looks too difficult, almost impossible.
Probably we had a transition from RNA to DNA a loooong time ago, but they have a 1 to 1 translation, and the intermediate steps look useful. But no one is sure anyway.
They propose a change where almost all the table changes and almost all the internal structure of the table change.
It is very strange that they have 20 amino acids and no stop code. A proposal with 19 amino acids and a stop code looks more sensible. We know that it is possible to add new amino acids to the table (with enough time). I think the main problem is that using 19 amino acids and a stop code breaks the magical part of predicting the number 20 with pencil and paper.
To make the table work, you need the correct transfer-RNA. To get all the symmetries in their model you need to be really lucky. In the block model of 15+1 you any random selection of tRNA is fine if it ignore the last base.
Another big problem is that they predict that half of the proteins would have been constructed backward. But as they say this make proteins not fold correctly. They try to avoid the problem using palindromic proteins, that is not supported by evidence.
This bacteria is introduced to an environment that has all it needs to spread quickly. There's absolutely nothing out there that it has to compete with. There's nothing out there consuming it or infecting it or otherwise inhibiting its growth other than a lack of whatever nutrient it consumes.
Rabbits went from 0 to over 200 million in under 200 years in Australia, and that's with snakes and disease. Apparently they spread across the continent in just 50 years.[1] Rabbits generally reproduce at a small fraction of the rate of bacteria, although exceptions exist.
Note: I'm not saying humans definitely introduced bacteria to Venus and that's the source. I'm saying if conditions are by some chance ideal, and these things are apparently thriving in the atmosphere, it shouldn't be hard to spread across the planet incredibly fast.
[1] https://www.nationalgeographic.org/article/how-european-rabb...
So not only do we have no good explanation for phosphine, we do not have a good explanation for the unknown absorbers. Well, we do have one good explanation although it seemed unlikely and that is life. Given that this is second effect that could be explained with microbes I feel it adds that much more weight to the theory.
Hopefully if they can get a probe out there they would be able to tell definitively if it was Soviet contamination or not, although I'm not sure how they would be able to do that. I could see them ruling it out (some entirely different DNA structure or something) but not sure how they'd say 100% that it was Soviet in origin.
Even if spores did survive the space trip (actually quite plausible, [0], venus trip is ~110 days), the atmosphere is extremely dessicating and acidic (SO2, SO3, H2SO4), and the ground is too hot for any known life. The dessication and osmotic pressure is the real kicker. It's very unlikely spores would germinate without rehydration.
[0] https://www.nasa.gov/mission_pages/station/research/news/eu_...
[1] https://www.nytimes.com/1966/03/06/archives/soviet-says-venu...
This of course does not account for other differences such as the rate at which microbes are transported into Earth's atmosphere, and whether that possibly habitable layer on Venus is stable enough to sustain a population.
1. Bombarded mars with junk (everything from the astroid belt and some rocks from the kuipler belt) to raise its mass to somewhat earth level. We'd have to be careful not to mess up Mars's orbit too much. 2. Slurp some of venus's thick atmosphere into a massive space tanker 3. Dump the atmosphere onto Mars++ 4. Let time and some engineered bacteria/plants clean up the mess
That's my long term goal if I become immortal.
https://selenianboondocks.com/2013/11/venus-isru-what-do-we-...
Which as far as I can tell isn't terrible if you don't breath it in and if you do the official allowed exposure time is 10 minutes for 5 ppm. I would recommend you wear goggles in addition to breathing equipment, though.
Presumably that's 5ppm under terrestrial conditions, Venus at 40km has substantially higher pressure, more than is explained by the higher temperature alone, so any given ppm is a greater number of molecules per cm³, right?
The Wikipedia page on Venus's atmosphere suggests that at that altitude Venus's atmosphere is a sulphuric acid haze at 110°C and about 2atm of pressure, which, even if there was something to walk on, doesn't sound like you'd be able to walk around with just an oxygen supply for very long.
That doesn’t rule out a ‘contamination’. But considering this is just another observation in a long line of interesting data I think makes it less likely.
(don't read the Plot on Wikipedia if you're planning to read the book)
>What was that "Famous Philip K. Dick Letter" regarding Lem?
>On September 2, 1974 Philip K. Dick sent the following letter to the FBI (Please keep in mind Mr. Dick was most probably suffering from schizophrenia):
And Stanislaw Lem returned the complement by writing "Philip K. Dick: A Visionary Among the Charlatans" in 1975, which got him expelled from the SFWA in 1976.
https://www.depauw.edu/sfs/backissues/5/lem5art.htm
>ABSTRACT
>Philip Dick does not lead his critics an easy life, since he does not so much play the part of a guide through his phantasmagoric worlds as give the impression of one lost in their labyrinth. He has stood all the more in need of critical assistance, but he has not received it. A characteristic of Dick ’s work, after its ambiguity as to genre, is its tawdriness, which is reminiscent of the goods offered at country fairs by primitive craftsmen who are at once clever and naive, possessed of more talent than self-knowledge. Dick has as a rule taken over a rubble of building materials from the run-of-the-mill American professionals of SF, frequently adding a true gleam of originality to worn-out concepts, and erecting with such materials constructions truly his own. The world gone mad, with a spasmodic flow of time and a network of causes and effects which wriggles as if nauseated, the world of frenzied physics, is unquestionably his invention. If Dick’s writings are neither of uniform quality nor fully realized, still it is only by brute force that they can be jammed into that pulp of materials, destitute of intellectual value and original structure, which makes up SF. Its fans are attracted by the worst in Dick—the typical dash of American SF, reaching to the stars, and the headlong pace of action moving from one surprise to the next—but they hold it against him that, instead of unraveling puzzles, he leaves the reader at the end on the battlefield, enveloped in an aura of mystery as grotesque as it is strange. Yet his bizarre blending of hallucinogenic and palingenetic techniques have not won him many admirers outside the ghetto walls, since outsiders are repelled by the shoddiness of the props he has adopted from the inventory of SF.
Discussion:
https://news.ycombinator.com/item?id=8801011
https://english.lem.pl/index.php/faq#SWFA
>Why was Stanislaw Lem expelled from the SFWA (Science Fiction Writers of America) in 1976?
>Lem has always been critical of most science fiction, which he considers ill thought out, poorly written, and interested more in adventure that ideas or new literary forms. (...) Those opinions provoked an unpleasant debate in the SFWA [the "Lem affair"]. Philip José Farmer and others were incensed by Lem's comments (...) and eventually brought about the removal of the honorary membership(...). Other members, such as Ursula K. Le Guin, then protested the removal (...) and the SFWA then offered Lem a regular membership, which he, of course, refused in 1976. Asked later about the "affair," he remarked, that his opinions of the state of science fiction were already known when he was offered an honorary membership (...). He also added he harboured no ill feelings towards the SFWA or U.S. writers in particular, "...but it would be a lie to say the whole incident has enlarged my respect for SF writers".
I'm an absolute fan of PKD, and he was definitely at his best when exploring the surreal and unexplainable, the paradoxes, the philosophical, and also the minutiae of the "uninteresting" parts of people's lives. Like someone said in the intro of his collected stories, PKD's characters themselves are often cardboard thin, and his props likewise. Taken at face value, the "pure" scifi bits of his stories aren't particularly interesting; but it's fascinating how he cares about what a time-traveler does for a living, and when a service call from the future goes horribly wrong, it's the minutiae about the repairman's life that matters, not the "tech". When someone is stuck in a parallel universe, their possible savior might only be interested in what's in it for her as profit. When someone is stuck in a Nazi-ruled world, we still learn he sells fake antiques for a living.
If someone lives in a backwards time-travelling stream ("Your Appointment Will Be Yesterday") this is never really explained. PKD doesn't care about this, he cares about how it affects his characters. And the story is never fully resolved, not in a tidy way -- it often ends up more confusing than it started!
So I guess I find myself in agreement with Stalislaw Lem here.
What are the odds?
Almost as likely as the suggestion that just this once, swamp gas really is evidence of aliens.
Also, it is probably panspermia from Eartg too!! Call me dull, but I see 0 chance what so ever that it developed natively. If it were Mars I would have believed it developed naturally... Here? Venus???!!! Panspermia all the way
So maybe life could have had time to develop natively before this event, and then would have migrated to the habitable zone of the atmosphere later.
Source: https://en.wikipedia.org/wiki/Atmosphere_of_Venus#:~:text=It....
It would be cool if somehow magically the life detected were native to the planet, but I very, very much doubt it. Panspermia from Earth is the most likely scenario
At this point, I fully embrace that the teams doing the research can't find a natural abiotic explainer for the phosphine simply because there isn't one
https://en.wikipedia.org/wiki/Geology_of_Venus#Ancient_liqui...
This is from studies ranging from 2007 to 2016, so it's neither really obsolete or too new.
[0] - https://www.sciencealert.com/scientists-have-witnessed-in-re...
I don't think simple multicellularity has ever been something that seemed like a likely candidate as a particularly strong filter (although you could argue that it's a weaker filter combined with others)
Do we know what were the necessary atributes of those early multicellular organisms without which animals wouldn't be possible?
Now, broadly, I think (in my capacity as an armchair biologist) what we care about here is an nervous system, or something like it that is capable of fast communication and complex feedback loops that can be built into complex "computation". Interestingly, nervous systems aren't present in sponges, which are most likely the basal animal group (and which are immobile), but are present in all other animals. I'm therefore speculating that "able to develop a nervous system" could be the filter we care about for behavioural complexity.
Being non-photosynthetic (so more advantage to being able to move around and find food), not having cell walls (so potentially more able to be motile, and form flexible structures), as well as just whether there are existing cellular pathways that control ion gradients in a way that can be co-opted for communication (which are present in sponges) all seem like plausible things that could predispose a multicellular organism to develop nerves, but if it is a filter, it could well also be that it's really hard to develop something as complicated as nerves, and an early animal got very lucky.
Reminds me of a documentary I once watched, watching a timelapse of a vine growing upwards. It grows spiraling, and it looks like it is "looking" for where the walls are, adjusting its trajectory whenever it touches a wall.
It's fascinating, and for me it definitely does have some quality of "intelligence" to it.
There are two types of naive thinking one is we are children of god and god would never kill all of us and we are deeply rational beings when things get critical we will snap out of it and get things done. I believe in gospel of doubt and that there will be no miracles here. Environmentalists are already abandoning their field and reskilling not only because of lack of funding but lack of public attention and change.
That tells me that they weren't all together convinced/interested/passionate about it, so good for them for switching. One thing I've noticed from people who love their field of research and are absolutely convinced of it -- they don't care how much it pays or who believes them. They do it partly because ego (want to be the first or among the first for groundbreaking studies) but mostly because of genuine interest and curiosity and the desire to show the world what they've learned.
The biggest argument in favor of climate change being a true existential risk is if the conflicts it would spawn would result in a global war.
It's far more of a threat to human culture and knowledge than to human DNA. The latter is likely to survive it in some form - albeit probably not a very interesting one. The former is already showing signs of stress and climate change has barely started.
Frankly, my belief is the only thing needed to parlay climate change into an accelerant for human progress as opposed to believing it's a hurdle to leap over is for us to see it that way, and use it as an excuse to build energy generation technologies 100x better than our current ones. The focus on renewables is depressing, and the memes around the solution to climate change to be "use less, consume less, focus on more clean energy" are equally so, since they creates a cynical belief there is a tradeoff between energy use and conservatism. We can have both.
Alternatively, you can compare France to China, which has a greater CO2 footprint per capita, and half the GDP per capita.
https://en.wikipedia.org/wiki/List_of_countries_by_carbon_di...
https://en.wikipedia.org/wiki/List_of_countries_by_GDP_(PPP)...
Many climate change activists aren't even countenancing nuclear power, known to be sustainable as well as much safer now than even in the recent past. I strongly agree that we can have both, we just need to build it.
These aren't insurmountable problems, but they are pretty big. With solar, a person can stick it on their house. A grid-level installation can be built over time and starts paying for itself as soon as the things are plugged in.
Our current plans are targeting 2030 for massive carbon reductions, right? I don't see how starting a bunch of nuclear plants now really helps there. The most enthusiastic proponents of preventing global warming have always wanted to target 10-15 years out, so the energy isn't there for nuclear. Unfortunately. It would have been nice if we'd built a bunch of nuclear reactors 30 years ago.
PV manufacturing is complex and expensive. Most of the cost of PV is in the manufacturing machinery, since the raw materials are cheap. Adding new manufacturing capacity takes time.
It may be that PV can be ramped up faster than nuclear, but some of the new nuclear designs (NuScale and Oklo) could be cranked out pretty fast also.
As for time, the majority of this 20-30 years estimate consists of inertia and bureaucracy. As a country, we've built far more complicated (Apollo Project) and high-risk (Manhattan Project) things in the past in a compressed time frame, we had no choice then because we've faced clear existential risks. Our inability to countenance all this today says more about us as a society, than it does about the do-ability (within say a decade) of the task at hand.
I guess I can agree with you, but only as pessimist, which is a darn shame really.
Thank god. We need people who are logical and pragmatic, not ideological and dogmatic. I don't think anyone has done as much damage to the climate as environmentalists, by opposing nuclear power. Fortunately the climate (no pun intended) slowly seems to be turning.
I do think we should reinvest in nuclear power at the same time we're making other reforms to the energy sector and economy.
I think suburban homeowners and their organized interests have had much more to do with nuclear power. I am an "environmentalist" and am largely pro-nuclear power (although less than before due to increasing cost competitiveness of renewables).
Actual environmentalists (ie. people who are passionate about saving the environment and also analytical thinkers) like Stewart Brand have been on top of this for a while.
Great Filter is neat because it bundles many different solutions together into one class. Any solution saying that civilizations in the Milky Way are incredibly rare is basically a variation on Great Filter.
>why should we assume anything about our ability to determine life beyond our Solar System?
It isn't farfetched to assume that sufficiently expansionist/numerous Kardashev type 2+ civilizations should be easier to detect from Earth than bacteria on Venus.
I think you are in fact laundering the very large assumption you're making.
However, it does seem that the Milky Way is not collonised (not even the other galaxies as far as we can tell), and if that's truly the case, then it would suggest that there is some kind of filter barring all civilizations from ever doing it.
I consider interstellar travel not ever being viable a legitimate filter.
Of course there is a plethora of other solutions as well.
I also wanted to point out that life on Venus would not even necessarily move the great filter. It is possible, though not experimentally proven, that lifeforms could survive a cataclysmic ejection from one planet after an asteroid impact and float to another planet in the same system. In other words, the life on Venus may have come from Earth or vice-versa.
"ANY AND EVERY" is not remotely a part of any plausible premise of either the Great Filter or the Fermi paradox. Please be charitable in stating assumptions of theories you disagree with.
Space is difficult, interstellar space exponentially more so. It isn't necessary to make any claims about any or all civilizations if the nature of physics alone makes it extremely unlikely for any species, however curious, to ever make it out of their local gravity well, much less sustain the technological infrastructure, knowledge base, energy consumption, unified political will (despite vast cultural and biological evolution) and control over every other variable across millions of years as a species to be able to stumble across our planet even once among the billions upon billions of galaxies' worth of stars in the observable universe.
One might say "it only has to happen once." I submit that it could have happened a thousand times and we could still never know.
So it seems reasonable that if any interstellar civilization were out there, one would have found us by now, or their presence would be obvious to us. After all, Rome knew of China, even if they never directly interacted, and Spain eventually stumbled across the New World. Von Neumann probes make sense because it doesn't occur to us that the chances of any arbitrary path along the universe intersecting with a star would be effectively zero. We look up at the night sky and we can see so many of them, and they seem so close together, obviously you'd run into one no matter which way you went, sooner or later. Right?
It's more comforting to make up rationales as to why we might be alone than deal with the ramifications of being surrounded by life we may never see in a universe in which the entirety of physical reality amounts to a rounding error in a zero.
[0]https://en.wikipedia.org/wiki/Hubble_Deep_Field
[1]https://www.theatlantic.com/technology/archive/2014/12/the-c...
There's a point where it's all just "big". A million and a billion seem equally big. Even though, as it has been said before, that the difference between 1 billion and 1 million is about 1 billion.
There are so many fundamentally difficult problems with deep space exploration, that it may never be logistically possible to over come them. And that's of the ones we know about.
If a single civilization in our galaxy made a machine capable of replicating itself and going to other star systems less than a billion years ago, we should have seen that.
> it doesn't occur to us that the chances of any arbitrary path along the universe intersecting with a star would be effectively zero
I fail to see how this is a strong critique of Von Neumann probes, maybe you can clarify.
Allow me to attempt to clarify.
Let's say a civilization creates Von Neumann probes. Ignore whether such devices are even technically feasible. It sends these Von Neumann probes out into the universe in all directions.
The chances of any one of them ever encountering anything larger than a grain of dust before the heat death of the universe is practically zero. In almost all possible universes, all of the probes are swallowed up by the void. In almost all of the rest, one probe finds enough material to be able to replicate, and all of those are swallowed up into the void.
The scenario whereby a stable chain of exponential reproduction and growth via interstellar transfer occurs lasting long enough for a significant amount of stellar matter to be consumed and for an obvious trace to be left which just happens to be visible to us, is not the most likely scenario in a universe where such devices exist, it is still so unlikely that its feasibility borders on requiring sorcery. Because the universe is just that empty.
It's the sort of idea that only works on graph paper assuming a "perfectly spherical cow in a frictionless vacuum" kind of universe. The lack of a universe awash in Von Neumann probes is not a strong argument against the existence of life or advanced civilization in the universe, it is, itself, a strong argument against the feasibility of Von Neumann probes.
If the goal is to mine the resources of one specific location, then a targeted probe makes sense. But if the goal is to proliferate and explore (or consume) as much of the universe as possible as efficiently as possible, then targeted probes seem less likely to succeed over the scale of time necessary.
I'd argue that your argument is either
a. not intrinsically true of complex probes or
b. just a modified version of the great filter argument
You could imagine an advanced civilization that creates an artificially intelligent probe that is pretty effective at problem solving and resilient to these sorts of failures. Even if targeted probes have to remain active, there is no reason they couldn't consume energy harvested from their origin world to course correct.
If your claim is that every form of intelligence will inevitably fall to mechanical or software failure, etc. then that claim seems to just be identical to the great filter claim.
> targeted probes seem less likely to succeed over the scale of time necessary.
Your own GP seems to provide a very compelling reason why this is not true.
>But if the goal is to proliferate and explore (or consume) as much of the universe as possible as efficiently as possible, then targeted probes seem less likely to succeed over the scale of time necessary.
Less likely than non targeted ones that you say wouldn't get past the first generation?
Haha okay. I think most would view this as a pretty uncharitable assumption (appears contingent on these civilizations not having telescopes or AI), but if that's your view I can understand why we disagree.
This is why no civilization would randomly fire off Von Neumman probes in random directions. They would understand that this is a problem.
If you want to efficiently use them, you fire them at nearby stars. They will either find materials and restart the process, or they won't (and potentially report this, but it's not required). A non-zero number of them may encounter sufficient material (given how plentiful planets seem to be, that's a fair assumption). Those star systems would now fire off a bunch of probes, at near stars. Rinse and repeat. It's a slow process, initially, but given the exponential nature, it should be surprisingly quick.
"Aiming" at star is not something that's too complex even for us. It might require mid-course corrections to account for errors, but we could build a probe that would conceivably reach a star. Ensuring it would be alive and operational by then is more challenging, but it is an engineering one. Actually entering the star's orbit might be even trickier depending on relative speed. But that's peanuts for a civilization that could build such things.
> The lack of a universe awash in Von Neumann probes is not a strong argument against the existence of life or advanced civilization in the universe, it is, itself, a strong argument against the feasibility of Von Neumann probes.
It is. But that's assuming we can even recognize one.
Given modern technology, we would be able to observe both without being noticed. It would be pretty trivial from space. It wouldn't be quite so trivial close up, but it would be possible.
A time difference of ten thousand years? The invisibility would be rather more effortless, and might even include direct memory manipulation in the victims.
A million years? Can anyone even imagine what a million year difference would look like? Never mind the technology - we can't even imagine what its motivations would be.
So assuming an advanced civ is going to do what we'd do - build ships, colonise, hoard and transform resources - is more than a little naive and unimaginative.
It's not unlike a protohominid assuming that life is about hunting, and any other two legged creature they meet is going to want to talk about flint knapping and these new arrowhead shapes.
The assumption is weaker than you suggest. It's not that your typical advanced civ will do what we'd do, just that some proportion (perhaps extremely small) of civilizations will be expansionary.
Any process that involves replication will eventually need more resources.
The idea is that "probability mass they'll cross paths with another and each can mutually grok the other exists" is a monotonically increasing function of the number of other civilizations, which bridges the problem you've identified.
> 1. it extremely unlikely for any species, however curious, to ever make it out of their local gravity well
ie. it is more likely that they would go extinct before making it out of their local gravity well, which means the discovery of other life local to us would make it substantially more likely that filter preventing us from attaining interstellar travel is ahead of us.
As we can see by this announcement they wouldn't have detected the first primal soup that formed life (we don't have any probes), but given enough time they would have sent a probe to our planet and detected single celled life, and they would have seen evidence of life.
At 5 light years (the closest start is just less than that) they wouldn't have had a chance before about 1900, and they might needed until 1960 (I give a range because there is room for debate on exactly what would be proof, they might have not been sure) to detect out radio transmissions. We would probably have made contact with them in the 1970s.
At up to 100 light years the above applies with more of a timeshift. After 200 we don't have the ability to detect ourselves (the technology of 1820 didn't give any emissions to go on.) I'm not sure if they would know there is a planet with water where we are (There has been great progress in detecting small planets but I don't know what their abilities are).
The farther out you go the harder it gets. Eventually they are still seeing the big bang form our galaxy and so have no idea life will eventually happen here (or where we will be as the universe is moving all along in directions that they cannot predict)
Back when we started broadcasting radio, we needed very powerful transmitters since the receivers were pretty primitive - you could make receivers with no power source at all (Galena radios).
Then we started using them for other purposes. Powerful radars appeared. TV was invented. Later on we added digital signals and most traffic shifted to binary for computer to computer communication.
Now we have things like WIFI and 5g. The problem is that the technology has advanced so much that cellular antennas can talk to puny transmitters from miles away, while the transmitters are only outputting milliwatts. We can also electronically 'steer' transmissions so they will 'point' at the other party (beamforming).
Long range communication is shifting to satellites and fiber optic cables. Those are pretty directional and not very strong signals, by comparison (and fiber optic of course has none). We have been slowly shutting down TV stations in favor of internet streams.
Civilian radars still exist but they are relatively weak. They are also slowly being phased out in favor of technologies like ADS-B, which broadcast a fraction of the power. GPS signals are very weak.
Military radars are also more sensitive than before - and increasingly look like background noise. Given the high emphasis on stealth, they are also more directional and lower power than before. And may not even be on all the time.
Given this, it is possible that, if you are taking a SETI approach, there's only a very small window before a civilization switches to more efficient and less noisy RF comms.
> At up to 100 light year
At 100 light years you'll have very faint, possibly undetectable signals, as the strength decreases with distance squared. Unless they are pointing at us.
A galactic civilization is expected to leave traces. The most advanced civilizations are expected to use a huge amount of energy (information is energy too). Even if we don't find spaceships, we could see otherwise unexplained high/low entropy regions. In fact, there is a theory that says that life is the most powerful entropy generator, and that Earth has a distinct IR glow because of it.
Currently, it doesn't seem there is anything preventing us from colonizing interstellar space in the far future. Lots of unanswered questions but the laws of physics don't exclude it.
The Great Filter theory is that because we don't see any sign of a galactic civilization, there is something in the way. It can be behind us (ex: the appearance of life) or ahead of us (ex: civilizations tend to get wiped off before they can colonize other star systems).
And even if the great filter is simply that even the most advanced civilizations can stay undetected (so no real filter), finding evidence that the great filter is less likely to be behind us make it more likely to be ahead of us (or inexistant).
> Imagine we knew God flipped a coin. If it came up heads, He made 10 billion alien civilization. If it came up tails, He made none besides Earth. Using our one parameter Drake Equation, we determine that on average there should be 5 billion alien civilizations. Since we see zero, that’s quite the paradox, isn’t it? No. In this case the mean is meaningless. It’s not at all surprising that we see zero alien civilizations, it just means the coin must have landed tails.
Just spent the time to read this whole paper, I think you're misstating some of the claims. A lot of people seem to be confused as to what is stated by the Great Filter/Fermi paradox/Drake equation.
First, let's define some terms (from wikipedia!): "The Great Filter, in the context of the Fermi paradox, is whatever prevents non-living matter from undergoing abiogenesis."
To be clear, the Great Filter is a solution to the Fermi paradox. If the Great Filter is true, then there is no paradox. The statement that there is no Fermi paradox is not the same as saying there is no Great Filter.
This paper suggests that there is a huge amount of uncertainty in $f_l$ and it actually can be quite small, meaning that it is not unlikely that we would see no alien life. (I won't comment on their choice of log-uniform priors, which does not seem intrinsically justified and lets them get much smaller results than if they had just picked uniform)
But that is the Great Filter argument! If there is a great filter, that would be a reason why $f_l$ would be lower and the fermi paradox doesn't occur. The paper never suggests that there is no great filter.
Now contextualizing to this discovery. If there is life on Venus, that changes our estimate of $f_l$, reducing our uncertainty and increasing the posterior probability mass towards life developing, which means that the fact that we haven't seen life must push the probability of development beyond that stage down or our current state of affairs is more unlikely than it was before.
Does that make sense?
> First, let's define some terms (from wikipedia!): "The Great Filter, in the context of the Fermi paradox, is whatever prevents non-living matter from undergoing abiogenesis."
I think you ended this sentence early. Wikipedia continues that sentence "...from undergoing abiogenesis, in time, to expanding lasting life as measured by the Kardashev scale."
In the context of the Fermi Paradox ("where are they?"), Bostrom is saying that he hopes the Great Filter is "whatever prevents non-living matter from undergoing abiogenesis" ($f_l$), but it might not be. The Great Filter might be a thing that is ahead of us, says he. And, yeah, the prior that it isn't abiogenesis is higher if we find life in our backyard.
So, you're right, finding life on Venus reduces some uncertainty with $f_l$ and pushes some of the probability mass down the Drake equation, which remains a chain of expected value multiplications, which is a bad way to combine probability distributions.
Bostrom's whole argument is predicated on the proposition that the galaxy "should be" teeming with life, and if the argument that it "should be" teeming with life is bogus (boiling down bathtub curved or otherwise not-normally distributed probability distributions to means/point estimates and then multiplying them, even if we had $f_l$ nailed down exactly), then I think that's a win for not worrying about Bostrom's argument so much.
But you are right, it's hard to say "don't worry about it!" if I don't well and clearly define what "it" is, or worse, define it wrong ("the great filter!"). Thanks for pushing this into better clarity.
Perhaps the paper wants to say that the problem with the Drake equation is intrinsic to multiplying expected probability, but what they're really doing is laundering their great filter assumptions upwards in the Bayesian hierarchy (ie. into their prior distribution hyperparameters and choice of distribution)
ie. they are still using expected values, they're just using them
This discovery would totally undermine the thesis of this paper. Here's the paper:
> While the analysis above required us to make our own judgment calls about how to represent the state of scientific uncertainty for each of these parameters, our qualitative result is robust to many of these assumptions and can be driven by our claimed uncertainty in f_l alone
This is much less impressive than it sounds. What this means is that if we could verify there is alien life on Venus that independently evolved, then the prior they have for f_l is massively off and their claimed uncertainty is way off. Using a log-uniform + the lowest estimate for f_l they can find in the literature already explains most of their results, not the mere process of multiplying expected probabilities.
> So, you're right, finding life on Venus reduces some uncertainty with $f_l$ and pushes some of the probability mass down the Drake equation, which remains a chain of expected value multiplications, which is a bad way to combine probability distributions.
The only reason they get such a low result is because they push a lot of the probability mass of $f_l$ super super super super far to the left. By their model, the probability that $f_l$ is less than 0.0001 is something like 42%... if we discovered independently evolved life on venus that would shift extremely far to the right and change their results completely.
Which would be terrible... but true to our history when discovering new world.
I have to wonder if they had contact with these MIT scientists pre-publication and that's what partially spurred this mission.
(RocketLab and Photon seem like a REALLY good platform for low-cost, small planetary missions like this. You can launch a mission for the price of a paper conceptual study and without the constraints of being a secondary payload, which is problematic for planetary missions with their narrow launch windows.)
It's unclear if these missions are currently designed to be able to detect phosphine though.
Although these organisms may not exist at all, for all we know...
https://www.sciencedaily.com/releases/2009/03/090318094642.h...
I can't see how bacteria could possibly evolve in the atmosphere but Venus is believed to have once had oceans.
But it's most likely just unusual high temperature processes in the Venusian atmosphere.
Something along the lines of:
> To do this, they spent the last several years running many species of phosphorous — phosphine’s essential building block — through an exhaustive, theoretical analysis of chemical pathways, under increasingly extreme scenarios, to see whether phosphorous could turn into phosphine in any abiotic way.
> The scientists found that phosphine has no significant false positives, meaning any detection of phosphine is a sure sign of life.
Apparently those know pathways don't work on rocky planets, which is why a detection on Venus is more interesting than a detection on Saturn.
I still expect the outcome to eventually be: "we have found a new pathway to Phosphine, that's consistent with a rocky planet", but it definitely seems like a discovery that warrants attention and further study.
Venus still has a sensible surface, although it's unclear if that concept makes sense for a gas giant. "Gas dwarfs" exist, which have a thick atmosphere around a rocky planet (i.e. around Earth's mass), but Venus probably doesn't qualify for that. It's sort of a continuum, though, so the dividing line is somewhat arbitrary.
As in, there is known chemistry that produces phosphine at the temperatures and pressures that exist on Saturn and Jupiter, but there is not known chemistry that produces phosphine at the temperatures and pressures that exist on Venus.
So for this particular chemistry, the difference between "gas giant" and "rocky planet" is still a helpful one.
My personal take on this is that the big claim doesn't seem entirely watertight. And claims like that have been taken apart quite quickly in the past.
> This means either this is life, or it’s some sort of physical or chemical process that we do not expect to happen on rocky planets.
> We really went through all possible pathways that could produce phosphine on a rocky planet. If this is not life, then our understanding of rocky planets is severely lacking.
So it's a matter of probabilities, not absolute certitudes.
My question is, why couldn't our current understanding of rocky planets be lacking?
Because "must be harboring life" rules this option out unconditionally.
The abstract clearly presents the question as an alternative, not "the only remaining possibility", as you stated:
"PH3 could originate from unknown photochemistry or geochemistry, or, by analogy with biological production of PH3 on Earth, from the presence of life"
It doesn't strike me as scientific to "ignore an unknown unknown", which would boil down to an assumption that we already know every possible reaction mechanism there is to know.
Discovering unknown chemistry would be groundbreaking of course, but the same goes for confirming extraterrestial life.
I've just read the paper and all this is right. Before that I haven't seen these claims so we are now in maybe life territory again. Sigh.
I've got an analogy for you. Lets say at one point you came to the conclusion that 2+2=4 and later I give you two apples and two apples, it would be quite unproductive to stop and ponder "Wait, my question is, why couldn't our understanding of addition be lacking?" Not when you have knowledge on hand to predict that you have four apples. Under-using your knowledge is not something conservative or cautious or in any way virtuous, it's simply wrong.
Searching for new hypotheses is cool, coming with new evidence is cooler, but doubting the hard-earned knowledge without a reason is not. In other words I'd suggest to stubbornly ignore unknown unknowns.
There are people who put their names on "we really went through all possible pathways" and you've put your name on a version of "huh?", excuse me for shortening it so brutally.
Agreed, any knowledge our civilization has is probably lacking to some degree. We kinda succeed by playing what we presently have on hand (and correcting it on the way).
https://www.planetary.org/articles/venus-phosphine-biosignat...
There is scientific evidence establishing that diatoms and other microorganisms are wafted up into Earth’s upper stratosphere and beyond 25–100 km above Earth’s surface.[1] From there, passing dust particles will transport a few of these microorganisms to the upper atmosphere of Venus.
Another transport route would be large meteoroids bombarding Earth with sufficient force to export Earth rocks and soil into interplanetary space.
[1]Alexa R. Van Eaton, Margaret A. Harper, and Colin J. N. Wilson, “High-Flying Diatoms: Widespread Dispersal of Microorganisms in an Explosive Volcanic Eruption,” Geology 41, no. 11 (November 2013): 1187–90, doi:10.1130/G24829.1; Milton Wainwright et al., “Isolation of a Diatom Frustule Fragment from the Lower Stratosphere (22–27 Km)-Evidence for a Cosmic Origin,” Journal of Cosmology 2013, volume 22 (August 9, 2013): 10183–10188.
In some ways humans are simpler than the cells they are made off. Yeah, you may know how to drive a car, but can you synthesize DNA? I find it fascinating that complexity goes up, when you zoom into a human. And cells exhibit all these behaviours.
There was this video I watched once, where a white blood cell was chasing a bacteria around. And it looked like a game of pacman. I would have never expected that a cell has some sort of self awareness, and is able to navigate its environment.
But you're right, cells are must more complex than our intuition often gives them credit for. But the time you get to a bacterium, fully 50% of the basic biomechanics of life are already in place. In fact, you can think of yourself as little more than a colony of specialized "bacteria" that self-organized into a whole that is greater than the sum of its parts, not at all unlike the way humans self-organize into groups (tribes, city-states, nation-states, corporations) that are greater than the sum of their parts.
I know the white blood cell animation you are talking about.
White blood cells are not self-aware. It might be helpful to picture cells (and even large animals) not as the discrete objects that are seen by the naked eye, but rather as a cloud of "stuff". In the middle is the meat; on the outside is various liquids, particles, and gases that leak out. So, the white blood cell isn't keeping an eye on the bacteria and chasing it. It's increasing contact with the "stuff" that it recognizes as foreign.
[0]: https://impacts.to/downloads/lowres/impacts.pdf#page=21
[1]: https://youtu.be/bU1QPtOZQZU?t=70
[2]: https://en.wikipedia.org/wiki/Panspermia#Lithopanspermia
This is certainly a fascinating notion, but it assumes arbitrary boundaries that have no real foundation in reality. Imagine instead what a staggering feat it is that the very cells that demonstrate all these remarkable biochemical behaviors can work in concert to drive a car!
I find this change in perspective to be quite instructive...that "humans" are not made of "cells," so much as collections of "cells" have developed a behavior that we describe as "human."
I think the framing is wrong here. A cell synthesizes DNA mechanically and without will or intent. The cell is made up of molecules that grab other molecules and operate on the other molecules to do something (repair, replicate, infect, etc.). When the right molecules come into contact with their targets, the synthesis just happens by the chemistry and physics that dictate the shape and movement of the molecules (modulo the stochastic and probabilistic process of other molecules moving around and becoming available). What we call life is an ever more complex set of molecules and their organization that allows their mechanical self-replication--and the other complex processes that extract and build all the constituent molecules from the environment (by building other molecular structures such as cell walls that also act mechanically on the molecules of the environment).
that being said, it does seem more likely that this will result in some new chemistry or a better understanding of conditions on venus than anything else
[0] https://trends.google.com/trends/explore?date=now%207-d&geo=...
“Pure phosphine is odorless“ (As per Wikipedia.)
On Venus, we have detected "unknown absorbers" that absorb portion of UV and visible light, these absorbers are seen in the form of clouds for 100 or so years. It's possible this detection is connected with those unknown absorbers and if so, it predates any human spacecraft.
Not only that, but it is doubtful that any kind of life would survive spaceflight and entry into an environment so vastly different than earth. If there is life on Venus, it is probably more extreme than extremophiles on Earth. Venera probes were not coated in phosphine producing extremophile bacteria.
All of the expert testimony I heard described Venus as far to acidic for any life on Earth [0]
Seems people so sure of life outside earth or not need it to be that way. Why can't people be okay with it just being ambiguous for now...
Science: must be drones or swamp gas or something
Data: Phosphine on Venus
Science: we have found life off of Earth!
This is why nobody trusts ya’ll anymore.
A PDF of the full paper is here: https://www.nature.com/articles/s41550-020-1174-4.pdf
"Astronomer here! Here is what is going on!
For many years, astronomers have speculated that the most likely way to find evidence of extraterrestrial life is via biosignatures, which are basically substances that provide evidence of life. Probably the most famous example of this would be oxygen- it rapidly oxidizes in just a few thousand years, so to have large quantities of oxygen in an atmosphere you need something to constantly be putting it there (in Earth's case, from trees). Another one that's been suggested as a great biosignature is phosphine- a gas we can only make on Earth in the lab, or via organic matter decomposing (typically in a water-rich environment, which Venus is not). So, to be abundantly clear, the argument here is to the best of our knowledge you should only get this concentration of phosphine if there is life.
What did this group discover? Is the signal legit? These scientists basically pointed a submillimeter radio telescope towards Venus to look for a signature of phosphine, which was not even a very technologically advanced radio telescope for this sort of thing, but they just wanted to get a good benchmark for future observations. And... they found a phosphine signature. They then pointed another, better radio telescope at it (ALMA- hands down best in the world for this kind of observation) and measured this signal even better. I am a radio astronomer myself, and looking at the paper, I have no reason to think this is not the signature from phosphine they say it is. They spend a lot of time estimating other contaminants they might be picking up, such as sulfur dioxide, but honestly those are really small compared to the phosphine signal. There's also a lot on the instrumentation, but they do seem to understand and have considered all possible effects there.
Can this phosphine be created by non-life? The authors also basically spend half the paper going through allllll the different possible ways to get phosphine in the atmosphere of Venus. If you go check "extended data Figure 10" in the paper they go through all of the options, from potential volcanic activity to being brought in from meteorites to lightning... and all those methods are either impossible in this case, or would not produce you the concentration levels needed to explain the signature by several orders of magnitude (like, literally a million times too little). As I said, these guys were very thorough, and brought on a lot of experts in other fields to do this legwork to rule options out! And the only thing they have not been able to rule out so far is the most fantastic option. :) The point is, either we don’t get something basic about rocky planets, or life is putting this up there.
(Mind, the way science goes I am sure by end of the week someone will have thought up an idea on how to explain phosphine in Venus's atmosphere. Whether that idea is a good one remains to be seen.)
To give one example, It should be noted at this point that phosphine has apparently been detected in comets- specifically, it’s thought to be behind in the comet 67P/Churyumov-Gerasimenko by the Rosetta mission- paper link. Comets have long been known to have a ton of organic compounds and are water rich- some suggest life on Earth was seeded by comets a long time ago- but it’s also present in the coma of comets as they are near the sun, which are very different conditions than the Venusian atmosphere. (It’s basically water ice sublimating as it warms up in a comet, so an active process is occurring in a water-rich environment to create phosphine.) However, the amounts created are nowhere near what is needed for the amounts of phosphine seen in Venus, we do not have water anywhere near the levels on Venus to make these amounts of phosphine, and we have detailed radar mapping to show us there was no recent cometary impact of Venus. As such, it appears highly unlikely that what puts phospine into Venus’s atmosphere is the same as what puts it into a comet’s coma. Research into this also indicates that, surprise surprise, cometary environments are very different than rocky ones, and only life can put it in the atmosphere of a rocky planet.
How can life exist on Venus? I thought it was a hell hole! The surface of Venus is indeed not a nice place to live- a runaway greenhouse effect means the surface is hot enough to melt lead, it rains sulfuric acid, and the Russian probes that landed there in didn't last more than a few hours. (No one has bothered since the 1980s.) However, if you go about 50 km up Venus's atmosphere is the most Earth-like there is in the Solar System, and this is where this signal is located. What's more, unlike the crushing pressure and hot temperatures on the surface, you have the same atmospheric pressure as on Earth, temps varying from 0-50 C, and pretty similar gravity to here. People have suggested we could even build cloud cities there. And this is the region this biosignature is coming from- not the surface, but tens of km up in the pretty darn nice area to float around in.
Plus, honestly, you know what I’m happy about that will come out of this? More space exploration of Venus! It is a fascinating planet that is criminally under-studied despite arguably some of the most interesting geology and atmosphere there is that we know of. (My favorite- Venus’s day is longer than its year, and it rotates “backwards” compared to all the other planets. But we think that’s not because of the way it formed, but because some gigantic planet-sized object hit it in the early days and basically flipped it upside down and slowed its spin. Isn’t that so cool?!) But we just wrote it off because the surface is really tough with old Soviet technology, and NASA hasn’t even sent a dedicated mission in over 30 years despite it being literally the closest planet to us. I imagine that is going to change fast and I am really excited for it- bring on the Venus drones!
So, aliens? I mean, personally if you're asking my opinion as a scientist... I think I will always remember this discovery as the first step in learning how common life is in the universe. :) To be clear, the "problem" with a biosignature is it does not tell you what is putting that phosphine into the Venusian atmosphere- something microbial seems a good bet (we have great radar mapping of Venus and there are def no cloud cities or large artificial structures), but as to what, your guess is as good as mine. We do know that billions of microbes live high up in the Earth's atmosphere, feeding as they pass through clouds and found as high as 10km up. So I see no reason the same can't be happening on Venus! (It would be life still pretty darn ok with sulfuric acid clouds everywhere, mind, but we have extremophiles on Earth in crazy environments too so I can’t think of a good reason why it’s impossible).
If you want to know where the smoking gun is, well here's the thing... Hollywood has well trained you to think otherwise, but I have always argued that discovering life elsewhere in the universe was going to be like discovering water on Mars. Where, as you might recall, first there were some signatures that there was water on Mars but that wasn't conclusive on its own that it existed, then a little more evidence came in, and some more... and finally today, everyone knows there is water on Mars. There was no reason to think the discovery of life wouldn't play out the same, because that's how science operates. (This is also why I always thought people were far too simplistic in assuming we would all just drop everything and unite as one just because life was discovered elsewhere- there'd be no smoking gun, and we'd all do what we all are doing now, get on social media to chat about it.) But put it this way- today we have taken a really big first step. And I think it is so amazing that this was first discovered not only next door, but on a planet not really thought of as great for life- it shows there's a good chance life in some for is ubiquitous! And I for one cannot wait until we can get a drone of some sort into the Venusian atmosphere to measure this better- provided, of course, we can do it in a way that ensures our own microbes don't hitch a ride.
TL;DR- if you count microbes, which I do, we are (probably) not alone. :D "
Usually in fiction that's because the discovery of alien life comes when they attack humanity. Hopefully these Venusian microbes don't have plans of Earth domination.
Do you happen to know more about "organic matter decomposing" as way phosphine gets produced? Microbes are certainly a pretty broad group here on Earth, and I wondered if there was something more specific about this metabolic pathway that could help our understanding of what was going on in the clouds of Venus.
[Yes, I googled a bit a couldn't find a good lay explanation]
Edit: changed from http://nasawatch.com/archives/2020/09/phosphine-detec.html to what appears to be the canonical source.