The Case for Life on Venus (cnet.com) 97
CNET describes Venus as "a toxic, overheated, crushing hellscape where nothing can survive." But they reported Friday that one astronomy team's hypothesis published last month "could prompt a reevaluation of how and where we look for life in the universe."
Carl Sagan speculated about life in the clouds of Venus back in 1967, and just a few years ago, researchers suggested that strange, anomalous patterns seen when looking at the planet in ultraviolet could be explained by something like an algae or a bacteria in the atmosphere. More recently, research published last month in the journal Astrobiology, from leading astronomer Sara Seager at MIT, offers up a vision of what the life cycle above Venus might be like. Seager has been a 21st century leader in the search for exoplanets, biosignatures, and worlds similar to our own. She's currently the deputy science director for NASA's Transiting Exoplanet Survey Satellite mission (aka TESS).
Seager and her colleagues suggest that the most likely way for microbes to survive above Venus is inside liquid droplets. But such droplets don't stay still, as anyone who's ever seen rain knows. Eventually they grow large enough that gravity takes over. In the case of Venus, this would mean droplets harboring tiny life forms and falling toward the hotter, lower layers of the planet's atmosphere, where they'd inevitably dry up. "We propose for the first time that the only way life can survive indefinitely is with a life cycle that involves microbial life drying out as liquid droplets evaporate during settling, with the small desiccated 'spores' halting at, and partially populating, the Venus atmosphere stagnant lower haze layer," the paper's summary reads. These dried-out spores would go into a sort of hibernation phase similar to what tardigrades can do, and eventually be lifted higher into the atmosphere and rehydrated, continuing the life cycle.
This is all speculation. Fortunately for Venusian life hunters, a number of astronomers and their instruments are trained on the complex planet. NASA is even considering a mission, dubbed Veritas, that could depart as soon as 2026 to orbit and study Venus and its clouds.
Meanwhile, more data from Venus, and perhaps new discoveries, may soon be incoming. The forecast for the planet remains, as it has for some time, cloudy with a chance of microbes.
Seager and her colleagues suggest that the most likely way for microbes to survive above Venus is inside liquid droplets. But such droplets don't stay still, as anyone who's ever seen rain knows. Eventually they grow large enough that gravity takes over. In the case of Venus, this would mean droplets harboring tiny life forms and falling toward the hotter, lower layers of the planet's atmosphere, where they'd inevitably dry up. "We propose for the first time that the only way life can survive indefinitely is with a life cycle that involves microbial life drying out as liquid droplets evaporate during settling, with the small desiccated 'spores' halting at, and partially populating, the Venus atmosphere stagnant lower haze layer," the paper's summary reads. These dried-out spores would go into a sort of hibernation phase similar to what tardigrades can do, and eventually be lifted higher into the atmosphere and rehydrated, continuing the life cycle.
This is all speculation. Fortunately for Venusian life hunters, a number of astronomers and their instruments are trained on the complex planet. NASA is even considering a mission, dubbed Veritas, that could depart as soon as 2026 to orbit and study Venus and its clouds.
Meanwhile, more data from Venus, and perhaps new discoveries, may soon be incoming. The forecast for the planet remains, as it has for some time, cloudy with a chance of microbes.
Something is fishy (Score:2)
Something is fishy because I cannot find the link to the original Nature paper. Was it retracted?
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The article was leaked then pulled, it will be officially published on Monday September 14th. Here's the googlecache of it. https://webcache.googleusercon... [googleusercontent.com]
I hope they cited me.
https://ntrs.nasa.gov/citation... [nasa.gov]
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starting with the gasses at the surface
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one cannot help but wonder what kind of catalyst would be that would terraform venus. starting with the gasses at the surface
You'd really need to pulverize the surface to a depth of about two miles, if you're thinking of a catalyst to turn the carbon dioxide into carbonate rock.
Life as defined by who? (Score:5, Insightful)
Re:Life as defined by who? (Score:4, Insightful)
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Re:Life as defined by who? (Score:5, Informative)
No liquid solvents like water, too much entropy for the most basic organic chemistry processes to be stable, and it would be near impossible for any 'cells' to keep their inside and outsides separate regardless of what materials they are made up of.
Re:Life as defined by who? (Score:4, Funny)
...and it would be near impossible for any 'cells' to keep their inside and outsides separate regardless of what materials they are made up of.
So you're saying it's possible.
Re:Life as defined by who? (Score:5, Interesting)
Don't underestimate just HOW temperate the middle cloud layer of Venus is, with earthlike temperatures, pressures, gravity, turbulence levels, significant atmospheric radiation shielding above, etc.
Main problem is the shortage of water, or rather, hydrogen in general. More sulfuric acid would actually be welcome; the hazes in the middle cloud layer are quite sparse, often with visibility levels that would be measured in kilometers. Lower cloud layer is denser (but hotter). Despite the heat, I'd think it to be more fitting for some sort of non-LAWKI extremophile; it seems to have a more diverse mix of chemicals, likely including phosphoric acid. Oh, and Venus's atmosphere probably contains iron, in the form of iron chloride.
Below the lower cloud layer, you get a sort of virga of evaporating droplets, as H2SO4 decomposes. Atmosphere is believed to be largely dynamically stable there, so not too much turbulence for updraft for spores (main turbulence is in the middle cloud layer, which is very similar to Earth's troposphere in terms of weather). But for everything we think we know about Venus, there's massive amounts of uncertainty.
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The problem is in how life could possibly evolve to live there. Taking into account Venus's contra orbit that could only have been caused by a major impact. It is likely that Venus was a living world and only the most extremophiles survived, it the atmosphere and possibly deep down in the crust. A living world that was well and truly extinctified, could have been us and yet likely that impact triggered the ice ages that promoted out intellectual evolution. Which in turn is routinely crushed by those self sa
Re:Life as defined by who? (Score:5, Interesting)
Not exactly true; It would just require something a lot more ordered than a lipid shell, (and thus not likely to form abiotically, and thus likely only to have existed from life starting in a less extreme environment, and being put under evolutionary pressures--- OR-- to have been synthetically engineered.)
See for instance, Aramid plastics. Some of them are thermally stable at the temperature ranges found on the surface of venus. (thermally stable up to 500C!!)
https://en.wikipedia.org/wiki/... [wikipedia.org]
To exist, a means of biologically converting free nitrogen into reduced nitrogen, then incorporating it in a very high energy molecule with very high levels of ordering and low error rates is necessary. That's a chicken and egg problem. If you solve that by having a less extreme past, then you could well have such lifeforms on the surface.
Re:Life as defined by who? (Score:5, Insightful)
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Yes, the periodic table of elements is surprising constraining and it seems that life on Earth has already explored all possibilities from the periodic table. Life on other planets will be similar because it is the only solution to the chemical puzzle.
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"Living things avoid decay into equilibrium"
Re:Life as defined by who? (Score:5, Informative)
Scientists have identified six possible "building sets" for life. The idea is that stable chemical chains in a particular solvent at a particular set of temperatures could function as life. We only have proof that one of these sets is actually possible, of course: proteins in water.
The others (from hottest to coolest) include fluorosilicones in other fluorosilicones at 400 to 500 celsius, fluorocarbons in liquid sulfur at 113 to 445 c., proteins in water at 0 to 100 c., proteins in liquid ammonia at -77 to -33 c., lipids in liquid methane at -183 to -161 c., and lipids in liquid hydrogen at -253 to -240.
Venus has a lot of sulfer and the right temperatures for the fluorocarbon/liquid sulfur type to potentially exist.
For reference: http://www.projectrho.com/publ... [projectrho.com]
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Yes everyone knows there are other ways life can exist, yet nobody has a solution or what they think we should be doing differently? Are you suggesting we not look for our type of biology? What would you do different. We already have a camera on the probe to catch any elephants.
Re:Life as defined by who? (Score:5, Interesting)
Hydrogen, Helium, Oxygen, Carbon, Nitrogen, Neon, Magnesium, Silicon, Iron, Sulfur, Argon...
Here is the list of the most abundant elements in living organisms:
Hydrogen, Oxygen, Carbon, Nitrogen, Phosphorus, Sulfur, Sodium, Iron...
As you can see, Life on Earth uses mainly the most common elements available to chemical reactions, because Helium, Neon and Argon can be dropped from the list. And it coalesces around Carbon based compounds, as Carbon has four free valences and thus can form the most different stable, or at least meta stable molecules. Carbon even has the property to form chains of itself, with other atoms grouped around, making it the prime candidate for complex compounds used in living things.
Yes, Silicon in theory could do the same, and it is quite abundant by itself. But it has a big disadvantage. Chemical reactions with Silicon takes dozen times the time than with Carbon, one reason why we use Silicon compounds to seal of holes and cracks in highly reactive environments. A Silicon based evolution thus would take dozen times the time as it takes for Carbon based Life.
And we can see that in the icy cores of comets and Kuiper belt objects in the Solar system, simple organic molecules like Methane, Ribose (a type of sugar), even some Amino acids are quite common. Thus, Carbon based Life using Ribose and Amino acids as the building blocks has a head start anyway.
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Humans are probably very unique. (By chance, or by higher programming).
We live on land, but have access to large oceans. We have opposable thumbs, that lead to efficient tool use. We are weak, but have higher brain capacities. We have moon to hold the planet's rotation steady. There is lots of fossils that lead to cheap energy, and eventually rocket fuels, and so on.
There could be microbial life on Venus, Mars, or many other places. There could be basic fauna on exoplanets. But I would be highly surprised i
one day... (Score:2)
Re:one day... (Score:4, Interesting)
One day we'll all have to sit back and acknowledge that we really are special and we are the only ones out there.
"Two possibilities exist. Either we are alone in the universe, or we are not. Both are equally terrifying" -- Arthur C. Clarke
/Hey, someone has to be first...
//In the Star Trek universe, the first race that conquered space found they truly were alone, and made it their mission to seed the rest of the cosmos with primordial life. That is their backstory for why the main sentient races look so much alike, they are all branches of the same evolutionary tree.
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That is, if you can get used to his alien accent. Great stuff indeed, but my gf can't stand listening to him.
Neither can my wife. So it's simple: we watch her chosen Disney movie if we can also watch a nice long episode about life aboard an O'Neill cylinder
If it was just an accent, it might be tolerable. He says it's a speech impediment. Regardless, why oh why do so many people think they can do a thing that revolves around talking while being physically incapable of talking properly. Boggles my mind. (I include the stuttering presidential candidate in that complaint.)
Isaac Arthur is up to 255 episodes, which is separately astonishing. Also more than half a million subscribers. And has episode sponsors. I sincerely wish he would make himself the writer
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I like his voice. It adds charm. It's funny and he acknowledges it ... one episode showed a picture of a whale getting shot from a cannon while Arthur tried to say "rail guns"
Then again, I like Geddy Lee's voice; Rush wouldn't be the same without it. Or should he have given up, too, and gotten a "real" singer?
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I like his voice. It adds charm. It's funny and he acknowledges it ... one episode showed a picture of a whale getting shot from a cannon while Arthur tried to say "rail guns"
Charm? You literally live with someone who can tell you how charming it isn't to have to listen to him struggle with the English language. And lose. Your own post is literally to someone else with a significant other with exactly the same problem. Multiply that by 7 billion. It's an obvious barrier to his potential audience. Your personal rationalization doesn't change that.
Then again, I like Geddy Lee's voice; Rush wouldn't be the same without it. Or should he have given up, too, and gotten a "real" singer?
I wouldn't know. Geddy Lee sounds like every other singer [xkcd.com] to me. The spoken word is radically different from singing, in every
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I think that part of the challenge is that we can only guess about why we arose.
There's this notion that "wherever on Earth we find liquid water we also find life, and life arose very early on Earth, so clearly it must happen quickly and easily wherever there's water in the universe". I think this is horribly misguided. The early Earth was a very alien place. We have no clue how the first forms of protolife on Earth functioned, but they probably functioned radically differently than life today does. Wha
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BS! The Drake Equation says you are wrong!
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One day we'll all have to sit back and acknowledge that we really are special and we are the only ones out there.
I've acknowledged it. You, for example, are just a figment of my imagination.
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Yes, quite. This is the 21st century. The headline should have "...Thieves Trousered Its e-Money Service".
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Hellscape, huh (Score:5, Funny)
"a toxic, overheated, crushing hellscape where nothing can survive."
Hey, people live in Los Angeles. Anything's possible.
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Colonize Venus (Score:4, Interesting)
Venus' atmosphere is 93 bar at the surface, you could do some pretty interesting high altitude ballooning in such a thick atmosphere. Even though the surface is very hot, at some altitude it gets cold. I don't know exactly how high you need to go, maybe 50 km and a pressure around 500 mBar? Not an a huge amount of pressure but with a large envelope it would lift a massive amount compared to high-altitude ballooning in Earth's atmosphere.
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Some may disagree [venuslabs.org]
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Thanks for that link. This is fascinating stuff.
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I was thinking more along the lines of a livable research vessel, as cramped as a submarine. I'm not interested in living on Venus. Supplies are difficult to produce if you can't touch the surface and must rely on shipments from Earth.
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Re:Colonize Venus (Score:4, Interesting)
The most Earthlike conditions are found in the high latitudes, around 53-54km if I remember right. Closer to the equator you get a somewhat less Earthlike balance - higher temperatures for a given pressure. Also, the superrotation speed near the poles is closer to an Earth day, and light levels are closer to Earth norms.
One of the neat things about "Venus ballooning" was published by Geoffrey Landis (an occasional visitor to Slashdot). While looking at ISRU methods that could be used to create lifting gases on Venus for probes, the two obvious gas choices were oxygen (from CO2) and nitrogen (straight from the air), each with about half the lifting power of helium on Earth. But.... nitrogen plus oxygen in your envelope? That's earth air. Your lift envelope itself is breathable. So forget about having a gondola underneath... you could have your crew within the envelope itself. Make it transparent and they can farm. Brightly-lit hanging gardens - a heaven floating over hell :)
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If you're floating in the part of the atmosphere where it's about as dense as Earth sea level, you're going to be roughly as likely to be hit by a meteoroid as you are on Earth. The small stuff won't reach you, big ones are rare. Most people dealing with inflatable structures on Earth aren't concerned by meteorites! Also, accidentally punching a hole in an air bag at ambient pressure is rather benign. Without pressure difference, the interior air will only very slowly bleed out. Hot air balloons can handle
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My favorite Venus atmosphere factoid is that the Empire State Building would float.
Balooning on Venus (Score:2)
Venus' atmosphere is 93 bar at the surface, you could do some pretty interesting high altitude ballooning in such a thick atmosphere. Even though the surface is very hot, at some altitude it gets cold. I don't know exactly how high you need to go, maybe 50 km and a pressure around 500 mBar
It has been done already! In 80-s the USSR launched a probe that launched a balloon on Venus: https://en.wikipedia.org/wiki/... [wikipedia.org] - it floated around for a while but then was sucked into the lower atmosphere (indicating that there are surprising air currents on Venus).
Mineral lakes and streams (Score:2)
Come on we need a Venus Lander/Drone .. the drone should investigate the galena and bismuthinite lakes and maybe catch a galena snowfall. There could even be liquid lead on the surface.
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The longest a lander lasted on the surface was just over two hours, not seeing hope for a rover... something on a balloon in atmosphere might be doable though.
Re:Mineral lakes and streams (Score:5, Informative)
The Venera probes were Soviet technology developed in the 1960s. Believe it or not, tech has moved on from then.
They were almost ridiculously simple in their basic design - an outer shell for structural strength, insulation to slow the rate of heat transfer, and then a phase-change material. At the temperature of phase change, it consumes heat energy in order to change phase from solid to liquid, and as a result, the temperature inside remains constant until the material has fully liquefied. And the Venusian environment proved friendly at times - for example, in one case, the lander's parachute ripped off, but the atmosphere was so dense that the probe survived the impact intact.
There's been countless designs for Venus rovers, from ones that use sails to outright purely-mechanical walkers like Strandbeests. But really, you don't have to go complicated. By the 1970s, the Soviets had gotten moving parts in the Venus environment working reliably. And indeed, that shouldn't be a surprise - many industries have to have moving parts inside extreme environments.
Longer-term survival on Venus requires either high-temperature electronics, or heat pumps. There's been significant progress with high-temperature electronics, although IMHO it's kind of a wasted path. Landis has done some work on the energy requirements for heat pumps for probe cooling, and they're not really that significant. Don't get me wrong, the surface of Venus makes everything harder, including pumping heat. Power as well. But it can be done. Even solar power works on the surface, despite the heat and dim - just at low power densities. RTGs have the disadvantage of having to have the hot reservoir at very high temperatures, but again, they're absolutely doable.
A potentially simpler approach is a phase-change balloon. This involves a probe with a simple, Venera-like climate control system, with no active cooling. But it also contains a pressurized tank of a liquid that can be boiled off into an envelope (such as ammonia), lifting the probe back to higher altitudes, cooling it it down, letting it recharge, and carrying it to a new location. It can then recondense its lifting gas and descend. The envelope materials are challenging, but workable. I think an amorphous polymer similar to Zylon (PBO) was a leading candidate last I checked. Coated carbon fibre also withstands surface environments.
An interesting method of lift under research is metal bellows balloons. They're basically like a giant accordion hanging over the probe, with a winch that can compress the bellows down to reduce its lift, or let the slack off so it can inflate and reascend. As they're metallic, there's no issues dealing with the heat.
Venus's dense atmosphere means that you get significant propulsive power for maneuvering with a relatively small propeller. It's dense enough that there's even some potential to dredge up loose surface material for sampling, using your propulsion system.
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For working at hotter than brick pizza oven temperature there has been a surprising lack of advances. There are no extant motors for rovers that can do that, you're talking theoretical baloney. Ditto for electronics that could make a computer or cameras. Recently there were circuits that could one day make a radio or temp sensor tested, but that's only part of what is needed. There is no heat pump that will work, the only game in town is what those russian landers did. Get cold as can be, then go for l
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The Soviets literally operated moving parts in Venus's environment in the early 1970s. You don't even have to have a penetration from the temperate interior.
Peer-reviewed research disagrees with you [aiaa.org].
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So you're not an enginer. Big difference between "moving parts" and a motor with enough torque for move a rover.
A piece of paper is not a working heat pump, Freshman 101 boy. There are no real world devices that can do the job.
Re: Mineral lakes and streams (Score:2)
Thatâ(TM)s a peer reviewed publication by NASA saying that a rover is feasible and there are no technological barriers. Youâ(TM)re dismissing it, what are your qualifications and what specifically do they misstate in that paper?
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You don't think technology might have advanced a little since then?
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at those temperatures, no. they cooled the thing before separation from the capsule and on surface played the game of "spread the heat around" and "melt the low melting temp block of material" until the thing toasted. I don't see any possibility of much improvement on that.
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Yes the CPUs will have to be kept cool (some regular CPUs can operate at about 100 celsius, so we don't need to cool to Earth's room temperature). We can use refrigeration to keep any electronics cool. There is no reason a refrigeration unit can't work at Venus temperatures .. granted it may need a massive radiator. Most metals, except lead, are solid at Venus surface temperatures anyway. Energy can be from solar or ideally an RTG or if environmentalists don't want RTGs launched, a solar powered refrigerati
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at those temperatures, no. they cooled the thing before separation from the capsule and on surface played the game of "spread the heat around" and "melt the low melting temp block of material" until the thing toasted. I don't see any possibility of much improvement on that.
Then your imagination is feeble indeed.
Land a probe equipped with a drill. Drill a couple of really deep holes and link them with a side bore at the bottom. Hammer piping into them and voila, a subsurface coolant loop. Pump coolant through it and your lander now has an indefinite lifespan. It's fixed in place, but it's also several tonnes and the size of a building to be able to drill a deep enough hole, so it can carry a rover with it. Let the rover out to roll around for an hour at a time, then retur
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We also can't rule out that we PUT life on Venus.. (Score:5, Interesting)
Degree of evolution? (Score:1)
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A few decades of evolutionary time is like a few milliseconds of flashbulb time.
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On rare occasion microbes or spores carried by the windows can get kicked out high into the atmosphere. They are likely up their to have mechanisms to survive to some degree in vacuum and upper atmosphere.
Just as the probe is leaving the outer atmosphere or is leaving orbit it might be sampling for the ideal candidates as it goes along.
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Venus used to be Earthlike at its surface, with extensive oceans (according to current science). It was not born in its hellish state. A major marker is the fact that its D/p ratio is nearly 2 1/2 orders of magnitude higher than Earth's.
If life evolved there before... was it all driven extinct? Or did some of it adapt? That's the question people are trying to answer.
I'm not personally a believer in life on Venus, but it's a serious topic of research.
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Well it's not really known what "easier" is .. maybe the "easier" conditions are much more hostile to life today because it has evolved out of that crucible. The conditions that seem hazardous today have actually been great or ideal to early stage life.
Dont think (Score:1)
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don't you think that being in a place that was not meant for humans will just create more chaos???
What does that even mean? No place in the universe was 'meant' for anything.
Could early Venus have supported life (Score:5, Interesting)
If there was a period of time early in the history of Venus, and there is the possibility that it had liquid oceans for ~2 billion years
https://en.wikipedia.org/wiki/... [wikipedia.org]
That could have allowed more complex life to evolve. When the climate changed, one could imagine macroscopic life adapting to the atmosphere - flying, floating etc. Large complex life forms could have protective skins to avoid water loss. There is a >5km thick region where temperatures and pressures could support vaguely earth-like life.
There is also the fun question of the limits of evolutionary adaptation given billions of years and a possibly constant, but extremely hostile environment.
?Previous attempts to look for Venusian bacteria (Score:1)
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"hellscape where nothing can survive" (Score:1)
So Detroit, then. Got it.
Wasn't that already widely known in 1960? (Score:2)
I mean back then the movie "La Nave de los Monstruos" came out which clearly showed that there was live on Venus.
https://www.youtube.com/watch?... [youtube.com]
Fascinating paper suggests mission beyond VERITAS (Score:2)
It's really a fascinating article. I think almost everyone here has not read it though which is pretty frustrating. It is a tour de force.
The key takeaway is that atmosphere is basically sulfuric acid with some water in it, very different from Earth. And yet there is a permanent cloud layer and inside that is where life is possible. (Boiling temperatures). Based on data from Venus landers and Earth science of the past 10 years, an entire possible life cycle for microbes is outlined in which cycling vertical
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Edits
700 million years ago not 400Mya.
Temperatures below boiling also available.
Fascinating calculations showing:
- that enough solar energy is available to a droplet to extract water from the atmosphere over seconds or minutes.
- that the diffusion rate of spores up toward the clouds is faster than the sedimentation rate
It's just a very fun paper!
Live feed (Score:1)
https://www.youtube.com/watch?v=y1u-jlf_Olo&feature=youtu.be
In other news... (Score:1)
... scientists discover revolutionary new method to produce phosphine gas from phosphorus, hydrogen, high pressure and sunlight, no organic process involved.