9 ms·

NASA mission to Venus in 1978 may have detected phosphine, a gas related to life

55 points by nathandaly 6y ago

FranOntanaya 6y ago
It's still puzzling how to argue about life on Venus' atmosphere with the lack of water. It'd be interesting to speculate about pathways for life to synthesize their own water from the available chemicals.
kamranjon 6y ago
I am so much more interested in Venus than Mars. They say the upper atmosphere is much more habitable than the surface of Mars. The density is apparently perfect for floating cities. I wonder why there is not more focus on it. Edit: here are some interesting links, a NASA concept manned mission that revolves around the floating concept: https://en.m.wikipedia.org/wiki/High_Altitude_Venus_Operational_Concept https://en.m.wikipedia.org/wiki/High_Altitude_Venus_Operatio... And some general info about colonizing venus, the advantages section outlines some of the reasons I'm excited about the idea: https://en.m.wikipedia.org/wiki/Colonization_of_Venus https://en.m.wikipedia.org/wiki/Colonization_of_Venus
- ruph123 6y ago
  Yeah it is remarkable that cloud cities on Venus are very quickly dismissed but terraforming a dead rock is...uh feasible?
  - alvarlagerlof 6y ago
    How would you build a cloud city?
    - mellosouls 6y ago
      Also, given they would be floating above hell, why would you?
      - ruph123 6y ago
        Mars' ground will not burn you to death, but the occasional solar flare due to missing magetosphere might, or the cosmic radiation, or the toxic soil.
      - yellowapple 6y ago
        That hell happens to be rich with all sorts of industrially useful chemicals. Seems like a decent reason to me.
    - evgen 6y ago
      Seriously? Start with your standard orbital space station. Add a bit more structural support and stiffening, then lower it into the atmosphere and use balloons to keep it at a set altitude. Voila, cloud village. Repeat as needed until your village is a city.
      - ppo11 6y ago
        Seriously? That isn’t how orbit works at all. With that plan you just reentered the whole thing, broke it into a million pieces, and rained it across the surface in a triumphant meteor shower of flame. Voila, everyone’s dead. Unless you had a plan for managing the atmospheric friction from orbital velocity that I didn’t read. In orbit things move sideways with respect to the surface. Fast. So the only way that works is if your “standard orbital space station” has enough propulsion to deorbit itself and hover in place — now that orbit is no longer cancelling gravity — until cubic kilometers of balloons that need to inflate (with what?) could hold it up. That amount of dV is barely theoretical at this point and would require several technological breakthroughs. You’re basically proposing deorbiting ISS without the atmospheric reentry and fiery death part, and given the similarities between our planets and their atmospheres it’s not a poor comparison.
        dang 6y ago
        Could you please stop creating accounts for every few comments you post? We ban accounts that do that. This is in the site guidelines: https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html. You needn't use your real name, of course, but for HN to be a community, users need some identity for other users to relate to. Otherwise we may as well have no usernames and no community, and that would be a different kind of forum. https://hn.algolia.com/?sort=byDate&dateRange=all&type=comment&storyText=false&prefix&page=0&query=community%20identity%20by:dang https://hn.algolia.com/?sort=byDate&dateRange=all&type=comme...
    - ruph123 6y ago
      First of all: Send some probes, explore, test.
    - duopixel 6y ago
      See Cloud Nine https://en.wikipedia.org/wiki/Cloud_Nine_(tensegrity_sphere) https://en.wikipedia.org/wiki/Cloud_Nine_(tensegrity_sphere)
  - rybosworld 6y ago
    I have a very hard time buying the idea that cloud cities are a more achievable idea.
    - darkerside 6y ago
      Every technological achievement seemed laughable before its time. Sure a "faster horse" was more understandable, but cars were actually more feasible.
      - ruph123 6y ago
        Not "every technological achievement seemed laughable before its time". Some were even imagined long before they came to reality. Also that does not make every idea imaginable also achievable. And conversely a lot of technological predictions were considered pretty seriously which are pretty far away from today (look at all the future predictions of the early 20th century. Flying cars and humanoid robots and all). Your comparison with existing cars replacing horses at that time is pretty out of whack with our abilities right now and the task of terraforming Mars, even the question IF making it habitable is even possible. We cannot even redirect asteroids...
        darkerside 6y ago
        Sure, I was being a bit flip with that response. But I think the point I was making stands. There are certainly innovations that sounds illogical but turn out to be very successful. Just because something sounds like a bad idea doesn't mean it is, it just means it hasn't worked yet. I actually don't think cloud cities sound that ridiculous either. Just like I also didn't think landing a rocket on its tail ever sounded unfeasible.
        ruph123 6y ago
        > But I think the point I was making stands. There are certainly innovations that sounds illogical but turn out to be very successful. Just because something sounds like a bad idea doesn't mean it is, it just means it hasn't worked yet. No because your point was about horses being replaced by cars, which is what people (and probably horses) were skeptical about at that time. In the same way IBM was saying that computers will never appear in homes, etc. But these devices were already there. The misconceptions were about predicting demand and miniaturization. This is completely different from terraforming. You are comparing "oh these devices sure never will be popular enough to make this other thing obsolete" with "lets nuke the Mars to create an atmosphere so we can live on it" (always winter, yeay).[0] Your argument is bad because by saying "technologies were laughed at in the past" every technology that sounds laughable should be taken seriously? No. This is the same trap that Theranos investors had fallen in. It is all a fantasy. We humans are very bad at estimating what is possible and what not. E.g. our inability to divert asteroids [1]. That is already a hard problem and currently not possible to do. I am not against crazy technological ideas, for example the space elevator had a surprisingly good feasibility to being realized before we polluted our planet's atmosphere with junk. Terraforming Mars is in the Theranos land of crazy ideas though. > Just like I also didn't think landing a rocket on its tail ever sounded unfeasible. Maybe because that was already demonstrated in the 90s [1]. [0]: https://www.space.com/elon-musk-nuke-mars-terraforming.html https://www.space.com/elon-musk-nuke-mars-terraforming.html [1]: https://www.youtube.com/watch?v=4Wrc4fHSCpw https://www.youtube.com/watch?v=4Wrc4fHSCpw [2]: https://www.youtube.com/watch?v=wv9n9Casp1o https://www.youtube.com/watch?v=wv9n9Casp1o
  - omk 6y ago
    Because building a cloud city isn't not end of the problem (and not a small one in itself). Sustaining a cloud city is very difficult. Terraforming Mars is being considered for the fact that it could be a near permanent solution.
    - wolfram74 6y ago
      "permanent" how? The fact that it has ended up a dead rock implies that that's its steady state. You make mars habitable, it'll probably require a perpetual gardening effort to keep it that way.
      - cgriswald 6y ago
        It would be effectively permanent. The sun would strip the atmosphere over a period of time on the order of a hundred million years. If we could terraform it in the first place maintaining it would be trivial.
      - nobodyandproud 6y ago
        https://astrobiology.nasa.gov/news/how-to-give-mars-an-atmosphere-maybe/#:~:text=An%20artificial%20magnetosphere%20of%20sufficient%20size%20generated%20at,%28or%20320%20Mars%20radii%29%20away%20from%20the%20planet https://astrobiology.nasa.gov/news/how-to-give-mars-an-atmos....
        wolfram74 6y ago
        I've talked with Dr. Green about the parasol idea, we still need to do a stability analysis since L1 is unstable, how much effort will it take to keep the dipole in place given the solar wind can fluctuate by an order of magnitude in either direction of the average. It's a fun problem.
        nobodyandproud 6y ago
        I wonder if having an adjustable center of mass would solve this problem. A mass ejection method would have to be maintained too often, but CoM adjustments can largely be automated (at least in principle).
  - nobodyandproud 6y ago
    The idea is intriguing, but floating cities makes me think there’s little tolerance for error (or a very easily reachable point of no return). The platform itself has to be constantly maintained, which requires a crew. Military or at least cruise ship with disciplined crewman, rather than anything civilians can be trusted or expected to maintain.
    - ruph123 6y ago
      Maybe the expectations of a "cloud city" should also be lowered. I guess it would be more like the ISS and less like Lando's station. The general idea of colonization of other planets is in general much farther away than your average tech billionaire wants us to think :)
    - sdenton4 6y ago
      I think you can design in error tolerance, with a bit of imagination. Imagine a flotilla of connected balloons, instead of one giant balloon; build in enough tolerance that a sagging balloon is supported by its neighbors until it can be fixed up. Ultimately, it's a question of building a floating thing, and keeping it floating. This strikes me as not-too-hard, compared to the usual space problem of trying to hold oxygen in a bubble in a vacuum. You just need a sustainable way to 'recharge' the balloons; that really just means filtering lighter gasses from the air and pumping them in faster than they leak out. The Venus atmosphere is primarily CO2 with a bit of nitrogen; the game is then filtering out CO2 and filling the balloons with nitrogen. Coincidentally, we have people putting lots of thought into efficiently filtering CO2 from air already...
      - gremlinsinc 6y ago
        Does it need to float? Could not some sort of mountain plateau work that's the right altitude but perfectly solid ground, just high in the sky?
        nobodyandproud 6y ago
        The safe height is on the order of 50 to 60 kilometers up, so that’s a tall order.
- ddevault 6y ago
  I'm no expert, but one thing which concerns me about Venus is the feasibility of sourcing local materials. It would be way more expensive to fetch resources from the surface and carry them up to floating cities, even in the energy cost alone, not accounting for the hellish conditions the equipment must endure - for thousands of duty cycles. On Mars, the regolith is right there. You can just scoop it up and use it. Much easier to turn into buildings, extract resources from it, and so on. I think we can colonize Venus, and ultimately should, but it presents a lot more problems than Mars. Mars makes a lot of sense as a first step.
  - officialjunk 6y ago
    why not try the moon first, before mars?
    - ddevault 6y ago
      We should definitely do both, and we'll almost certainly have people on the Moon again before sending them to Mars, if for no other reason than to test some of the necessary technology. I hope that a permanent human presence on the Moon becomes a reality soon. But there are lots of reasons to go to Mars, too. For one, it's much harder, which means a lot more innovation will be required to get there and set up a colony. Unlike Venus, though, these are one-time costs - the long-term economics of Mars are likely to be more sustainable. Mars is also richer in natural resources, not the least of which is gravity - we're not sure how much gravity humans need, but we do know that spending a lot of time in zero G is bad for our health. The Moon's gravity may not be sufficient for long-term individual habitation, or for rearing children. Mars also has an atmosphere, from which we can source useful gasses, and which provides (some) protection from radiation, and which gives it weather, making it a more dynamic and interesting place. In any case, if we can colonize Mars, the same technology is applicable to the Moon, and we'll almost certainly apply it as such around the same time.
- fnord77 6y ago
  gravity on venus is more similar to earth than mars, too
- neilshevlin 6y ago
  I've always had a soft spot for Venus. The floating city idea is not my favourite, perhaps for research there could be applications. A monumental breakthrough in carbon sequestration, in method and cost might do it for Venus though. But I mean monumental. Back of the envelope calculations say there's about 460 Quadrillion metric tonne of CO2. Sooo, maybe at a cost 1c per metric tonne we could get it done with a current day cost of 4.6 Quadrillion US Dollars or so. Or all the worlds GDP for about 50 years. But that assumes that there would be no benefits from doing that. Could be other applications from the byproducts being sold.
  - mdhen 6y ago
    it's always seemed to me that the serious problem with Venus is it's rotation speed. if it wasn't so slow I think you could turn it into a legitimately nice planet very long term. Mars on the other hand lacks the necessary macros, it's likely always going to be a rough place to live.
- darkerside 6y ago
  Grade school me always thought it was actually pretty simple. More heat means more energy. Just because we don't know how to harness it yet doesn't mean we can't. We live off of the sun. Why would were go farther away instead of closer? Maybe naive thoughts, but are they wrong?
  - tambourine_man 6y ago
    You need a heat gradient to take advantage of it. An uniformly hot place like Venus is a hard thermodynamic place. Mercury and our moon are actually interesting in that regard. I had similar fantasies as a kid, a huge pipe with a thermal fluid taking advantage of the difference in temperature between the cool and warm side of the planet/moon. But with today’s prices on solar panels, this will probably never happen.
- f6v 6y ago
  People on HN start this discussion whenever there’re any news about Venus/Mars. But at this point I don’t even care which planet we colonize first. As a layman, I think it’s an engineering problem and all we need is money. Let’s just go SOMEWHERE. Someone usually says: “Yeah but what about curing cancer first?!” Guys, the war on cancer(or HIV/Alzheimer’s/whatever) has been going on for decades. We can’t wait forever, as there’s always going to be next disease to take care of. “And what about eradicating poverty on Earth first?!” Just hear me out... imagine how many people we can put to work(with decent wage!) if we put enough money on the interplanetary flights? We’d invest in science, engineering, production... Well, I’ll keep dreaming.
  - ic0n0cl4st 6y ago
    Seems like a potentially great way to transfer a lot of wealth from taxpayers to the aerospace industry for a very long time with little oversight or roi.
    - f6v 6y ago
      In ideal world, we'd transfer wealth from football players, singers, actors, traders etc.
      - ic0n0cl4st 6y ago
        Or maybe we give more thought to the feasibility of space colonization and give people the ability to opt out of paying for this kind of adventurism? I work really hard and would rather my taxes go to helping out those living today, not maybe those living in 1,000 years.
        deleted 6y ago
        [deleted]
        entropea 6y ago
        I agree with you. It's driven by nothing more than sci-fi fantasy. Robots are the future of space travel and public funded inventions for those do end up bringing useful technological advances in the future.
SkyPuncher 6y ago
Similar discussion here: https://news.ycombinator.com/item?id=24467635 https://news.ycombinator.com/item?id=24467635
- mellosouls 6y ago
  Note though that its been superceded somewhat as the scientific conversation moved on: eg. https://www.nature.com/articles/d41586-020-03258-5 https://www.nature.com/articles/d41586-020-03258-5
fnord77 6y ago
"However, the detection of phosphine was suggested to be a possible false positive in October 2020,[11] and in January 2021 further research attributed the spectroscopic signal to that of sulphur dioxide.[12]"
- goodcanadian 6y ago
  This quote is not from the article and is only tangentially related to the article.
  - fnord77 6y ago
    it should be pretty clear where the quote is from.
    - gus_massa 6y ago
      Can I guess? Wikipedia? Never assume people will notice and understand correctly, it's much better to add a direct link. Anyway, it is very weird that the article talks about the 2020 announcement, but doesn't explain that is mostly debunked (as explained in your quote in the ggp comment).
      - goodcanadian 6y ago
        Contested, perhaps, but I think debunked is too strong of a term. I am acquainted with several of the people involved. While everyone makes errors from time to time, I find it very hard to believe Greaves, et al, would have been sloppy in any way. And, I think, the article was quite clear about the fact that the result had been called into question. Regardless, the article is about a different team, with a different instrument, and a different (historical) data set getting a result that may support the Greaves result. Talking about Greaves is largely tangential to the article.
gus_massa 6y ago
The accepted draft of the research paper is in https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2020GL091327 https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/202... Look at figure 10, graph O, P, Q in the last but one row. They are fitting the same data near 34 amu. The 3 vertical bars that show the error intervals are huge. (The SAD values are in page 8, item 3.) * In the graph O they fit the data using the expected curve of H2S+ and get a SAD value of 4.7 * In the graph P they fit the data using the expected curve of H3P+ and get a SAD value of 4.7 (again) * In the graph Q they fit the data using the expected curve of of mix of H2S+ and H3P+ and get a SAD value of 4.0. It's expected that with a mix you get a lower SAD, but it's clear that the error bars are so huge and the 3 fits so similar, that it's not possible to distinguish which one is the correct one. It looks like another case of overfitting.
xyzzy21 6y ago
This was debunked already. The phosphine didn't include any other markers for life and there are natural sources that are far more likely to create it. In any case, what allows bacteria doesn't mean jack for humans.

55 points by nathandaly 6y ago

It's still puzzling how to argue about life on Venus' atmosphere with the lack of water. It'd be interesting to speculate about pathways for life to synthesize their own water from the available chemicals.

kamranjon 6y ago

I am so much more interested in Venus than Mars. They say the upper atmosphere is much more habitable than the surface of Mars. The density is apparently perfect for floating cities. I wonder why there is not more focus on it. Edit: here are some interesting links, a NASA concept manned mission that revolves around the floating concept: https://en.m.wikipedia.org/wiki/High_Altitude_Venus_Operational_Concept https://en.m.wikipedia.org/wiki/High_Altitude_Venus_Operatio... And some general info about colonizing venus, the advantages section outlines some of the reasons I'm excited about the idea: https://en.m.wikipedia.org/wiki/Colonization_of_Venus https://en.m.wikipedia.org/wiki/Colonization_of_Venus

ruph123 6y ago
Yeah it is remarkable that cloud cities on Venus are very quickly dismissed but terraforming a dead rock is...uh feasible?
- alvarlagerlof 6y ago
  How would you build a cloud city?
  - mellosouls 6y ago
    Also, given they would be floating above hell, why would you?
    - ruph123 6y ago
      Mars' ground will not burn you to death, but the occasional solar flare due to missing magetosphere might, or the cosmic radiation, or the toxic soil.
    - yellowapple 6y ago
      That hell happens to be rich with all sorts of industrially useful chemicals. Seems like a decent reason to me.
  - evgen 6y ago
    Seriously? Start with your standard orbital space station. Add a bit more structural support and stiffening, then lower it into the atmosphere and use balloons to keep it at a set altitude. Voila, cloud village. Repeat as needed until your village is a city.
    - ppo11 6y ago
      Seriously? That isn’t how orbit works at all. With that plan you just reentered the whole thing, broke it into a million pieces, and rained it across the surface in a triumphant meteor shower of flame. Voila, everyone’s dead. Unless you had a plan for managing the atmospheric friction from orbital velocity that I didn’t read. In orbit things move sideways with respect to the surface. Fast. So the only way that works is if your “standard orbital space station” has enough propulsion to deorbit itself and hover in place — now that orbit is no longer cancelling gravity — until cubic kilometers of balloons that need to inflate (with what?) could hold it up. That amount of dV is barely theoretical at this point and would require several technological breakthroughs. You’re basically proposing deorbiting ISS without the atmospheric reentry and fiery death part, and given the similarities between our planets and their atmospheres it’s not a poor comparison.
      - dang 6y ago
        Could you please stop creating accounts for every few comments you post? We ban accounts that do that. This is in the site guidelines: https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html. You needn't use your real name, of course, but for HN to be a community, users need some identity for other users to relate to. Otherwise we may as well have no usernames and no community, and that would be a different kind of forum. https://hn.algolia.com/?sort=byDate&dateRange=all&type=comment&storyText=false&prefix&page=0&query=community%20identity%20by:dang https://hn.algolia.com/?sort=byDate&dateRange=all&type=comme...
  - ruph123 6y ago
    First of all: Send some probes, explore, test.
  - duopixel 6y ago
    See Cloud Nine https://en.wikipedia.org/wiki/Cloud_Nine_(tensegrity_sphere) https://en.wikipedia.org/wiki/Cloud_Nine_(tensegrity_sphere)
- rybosworld 6y ago
  I have a very hard time buying the idea that cloud cities are a more achievable idea.
  - darkerside 6y ago
    Every technological achievement seemed laughable before its time. Sure a "faster horse" was more understandable, but cars were actually more feasible.
    - ruph123 6y ago
      Not "every technological achievement seemed laughable before its time". Some were even imagined long before they came to reality. Also that does not make every idea imaginable also achievable. And conversely a lot of technological predictions were considered pretty seriously which are pretty far away from today (look at all the future predictions of the early 20th century. Flying cars and humanoid robots and all). Your comparison with existing cars replacing horses at that time is pretty out of whack with our abilities right now and the task of terraforming Mars, even the question IF making it habitable is even possible. We cannot even redirect asteroids...
      - darkerside 6y ago
        Sure, I was being a bit flip with that response. But I think the point I was making stands. There are certainly innovations that sounds illogical but turn out to be very successful. Just because something sounds like a bad idea doesn't mean it is, it just means it hasn't worked yet. I actually don't think cloud cities sound that ridiculous either. Just like I also didn't think landing a rocket on its tail ever sounded unfeasible.
        ruph123 6y ago
        > But I think the point I was making stands. There are certainly innovations that sounds illogical but turn out to be very successful. Just because something sounds like a bad idea doesn't mean it is, it just means it hasn't worked yet. No because your point was about horses being replaced by cars, which is what people (and probably horses) were skeptical about at that time. In the same way IBM was saying that computers will never appear in homes, etc. But these devices were already there. The misconceptions were about predicting demand and miniaturization. This is completely different from terraforming. You are comparing "oh these devices sure never will be popular enough to make this other thing obsolete" with "lets nuke the Mars to create an atmosphere so we can live on it" (always winter, yeay).[0] Your argument is bad because by saying "technologies were laughed at in the past" every technology that sounds laughable should be taken seriously? No. This is the same trap that Theranos investors had fallen in. It is all a fantasy. We humans are very bad at estimating what is possible and what not. E.g. our inability to divert asteroids [1]. That is already a hard problem and currently not possible to do. I am not against crazy technological ideas, for example the space elevator had a surprisingly good feasibility to being realized before we polluted our planet's atmosphere with junk. Terraforming Mars is in the Theranos land of crazy ideas though. > Just like I also didn't think landing a rocket on its tail ever sounded unfeasible. Maybe because that was already demonstrated in the 90s [1]. [0]: https://www.space.com/elon-musk-nuke-mars-terraforming.html https://www.space.com/elon-musk-nuke-mars-terraforming.html [1]: https://www.youtube.com/watch?v=4Wrc4fHSCpw https://www.youtube.com/watch?v=4Wrc4fHSCpw [2]: https://www.youtube.com/watch?v=wv9n9Casp1o https://www.youtube.com/watch?v=wv9n9Casp1o
- omk 6y ago
  Because building a cloud city isn't not end of the problem (and not a small one in itself). Sustaining a cloud city is very difficult. Terraforming Mars is being considered for the fact that it could be a near permanent solution.
  - wolfram74 6y ago
    "permanent" how? The fact that it has ended up a dead rock implies that that's its steady state. You make mars habitable, it'll probably require a perpetual gardening effort to keep it that way.
    - cgriswald 6y ago
      It would be effectively permanent. The sun would strip the atmosphere over a period of time on the order of a hundred million years. If we could terraform it in the first place maintaining it would be trivial.
    - nobodyandproud 6y ago
      https://astrobiology.nasa.gov/news/how-to-give-mars-an-atmosphere-maybe/#:~:text=An%20artificial%20magnetosphere%20of%20sufficient%20size%20generated%20at,%28or%20320%20Mars%20radii%29%20away%20from%20the%20planet https://astrobiology.nasa.gov/news/how-to-give-mars-an-atmos....
      - wolfram74 6y ago
        I've talked with Dr. Green about the parasol idea, we still need to do a stability analysis since L1 is unstable, how much effort will it take to keep the dipole in place given the solar wind can fluctuate by an order of magnitude in either direction of the average. It's a fun problem.
        nobodyandproud 6y ago
        I wonder if having an adjustable center of mass would solve this problem. A mass ejection method would have to be maintained too often, but CoM adjustments can largely be automated (at least in principle).
- nobodyandproud 6y ago
  The idea is intriguing, but floating cities makes me think there’s little tolerance for error (or a very easily reachable point of no return). The platform itself has to be constantly maintained, which requires a crew. Military or at least cruise ship with disciplined crewman, rather than anything civilians can be trusted or expected to maintain.
  - ruph123 6y ago
    Maybe the expectations of a "cloud city" should also be lowered. I guess it would be more like the ISS and less like Lando's station. The general idea of colonization of other planets is in general much farther away than your average tech billionaire wants us to think :)
  - sdenton4 6y ago
    I think you can design in error tolerance, with a bit of imagination. Imagine a flotilla of connected balloons, instead of one giant balloon; build in enough tolerance that a sagging balloon is supported by its neighbors until it can be fixed up. Ultimately, it's a question of building a floating thing, and keeping it floating. This strikes me as not-too-hard, compared to the usual space problem of trying to hold oxygen in a bubble in a vacuum. You just need a sustainable way to 'recharge' the balloons; that really just means filtering lighter gasses from the air and pumping them in faster than they leak out. The Venus atmosphere is primarily CO2 with a bit of nitrogen; the game is then filtering out CO2 and filling the balloons with nitrogen. Coincidentally, we have people putting lots of thought into efficiently filtering CO2 from air already...
    - gremlinsinc 6y ago
      Does it need to float? Could not some sort of mountain plateau work that's the right altitude but perfectly solid ground, just high in the sky?
      - nobodyandproud 6y ago
        The safe height is on the order of 50 to 60 kilometers up, so that’s a tall order.
ddevault 6y ago
I'm no expert, but one thing which concerns me about Venus is the feasibility of sourcing local materials. It would be way more expensive to fetch resources from the surface and carry them up to floating cities, even in the energy cost alone, not accounting for the hellish conditions the equipment must endure - for thousands of duty cycles. On Mars, the regolith is right there. You can just scoop it up and use it. Much easier to turn into buildings, extract resources from it, and so on. I think we can colonize Venus, and ultimately should, but it presents a lot more problems than Mars. Mars makes a lot of sense as a first step.
- officialjunk 6y ago
  why not try the moon first, before mars?
  - ddevault 6y ago
    We should definitely do both, and we'll almost certainly have people on the Moon again before sending them to Mars, if for no other reason than to test some of the necessary technology. I hope that a permanent human presence on the Moon becomes a reality soon. But there are lots of reasons to go to Mars, too. For one, it's much harder, which means a lot more innovation will be required to get there and set up a colony. Unlike Venus, though, these are one-time costs - the long-term economics of Mars are likely to be more sustainable. Mars is also richer in natural resources, not the least of which is gravity - we're not sure how much gravity humans need, but we do know that spending a lot of time in zero G is bad for our health. The Moon's gravity may not be sufficient for long-term individual habitation, or for rearing children. Mars also has an atmosphere, from which we can source useful gasses, and which provides (some) protection from radiation, and which gives it weather, making it a more dynamic and interesting place. In any case, if we can colonize Mars, the same technology is applicable to the Moon, and we'll almost certainly apply it as such around the same time.
fnord77 6y ago
gravity on venus is more similar to earth than mars, too
neilshevlin 6y ago
I've always had a soft spot for Venus. The floating city idea is not my favourite, perhaps for research there could be applications. A monumental breakthrough in carbon sequestration, in method and cost might do it for Venus though. But I mean monumental. Back of the envelope calculations say there's about 460 Quadrillion metric tonne of CO2. Sooo, maybe at a cost 1c per metric tonne we could get it done with a current day cost of 4.6 Quadrillion US Dollars or so. Or all the worlds GDP for about 50 years. But that assumes that there would be no benefits from doing that. Could be other applications from the byproducts being sold.
- mdhen 6y ago
  it's always seemed to me that the serious problem with Venus is it's rotation speed. if it wasn't so slow I think you could turn it into a legitimately nice planet very long term. Mars on the other hand lacks the necessary macros, it's likely always going to be a rough place to live.
darkerside 6y ago
Grade school me always thought it was actually pretty simple. More heat means more energy. Just because we don't know how to harness it yet doesn't mean we can't. We live off of the sun. Why would were go farther away instead of closer? Maybe naive thoughts, but are they wrong?
- tambourine_man 6y ago
  You need a heat gradient to take advantage of it. An uniformly hot place like Venus is a hard thermodynamic place. Mercury and our moon are actually interesting in that regard. I had similar fantasies as a kid, a huge pipe with a thermal fluid taking advantage of the difference in temperature between the cool and warm side of the planet/moon. But with today’s prices on solar panels, this will probably never happen.
f6v 6y ago
People on HN start this discussion whenever there’re any news about Venus/Mars. But at this point I don’t even care which planet we colonize first. As a layman, I think it’s an engineering problem and all we need is money. Let’s just go SOMEWHERE. Someone usually says: “Yeah but what about curing cancer first?!” Guys, the war on cancer(or HIV/Alzheimer’s/whatever) has been going on for decades. We can’t wait forever, as there’s always going to be next disease to take care of. “And what about eradicating poverty on Earth first?!” Just hear me out... imagine how many people we can put to work(with decent wage!) if we put enough money on the interplanetary flights? We’d invest in science, engineering, production... Well, I’ll keep dreaming.
- ic0n0cl4st 6y ago
  Seems like a potentially great way to transfer a lot of wealth from taxpayers to the aerospace industry for a very long time with little oversight or roi.
  - f6v 6y ago
    In ideal world, we'd transfer wealth from football players, singers, actors, traders etc.
    - ic0n0cl4st 6y ago
      Or maybe we give more thought to the feasibility of space colonization and give people the ability to opt out of paying for this kind of adventurism? I work really hard and would rather my taxes go to helping out those living today, not maybe those living in 1,000 years.
      - deleted 6y ago
        [deleted]
      - entropea 6y ago
        I agree with you. It's driven by nothing more than sci-fi fantasy. Robots are the future of space travel and public funded inventions for those do end up bringing useful technological advances in the future.

SkyPuncher 6y ago

Similar discussion here: https://news.ycombinator.com/item?id=24467635 https://news.ycombinator.com/item?id=24467635

mellosouls 6y ago
Note though that its been superceded somewhat as the scientific conversation moved on: eg. https://www.nature.com/articles/d41586-020-03258-5 https://www.nature.com/articles/d41586-020-03258-5

fnord77 6y ago

"However, the detection of phosphine was suggested to be a possible false positive in October 2020,[11] and in January 2021 further research attributed the spectroscopic signal to that of sulphur dioxide.[12]"

goodcanadian 6y ago
This quote is not from the article and is only tangentially related to the article.
- fnord77 6y ago
  it should be pretty clear where the quote is from.
  - gus_massa 6y ago
    Can I guess? Wikipedia? Never assume people will notice and understand correctly, it's much better to add a direct link. Anyway, it is very weird that the article talks about the 2020 announcement, but doesn't explain that is mostly debunked (as explained in your quote in the ggp comment).
    - goodcanadian 6y ago
      Contested, perhaps, but I think debunked is too strong of a term. I am acquainted with several of the people involved. While everyone makes errors from time to time, I find it very hard to believe Greaves, et al, would have been sloppy in any way. And, I think, the article was quite clear about the fact that the result had been called into question. Regardless, the article is about a different team, with a different instrument, and a different (historical) data set getting a result that may support the Greaves result. Talking about Greaves is largely tangential to the article.

gus_massa 6y ago

The accepted draft of the research paper is in https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2020GL091327 https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/202... Look at figure 10, graph O, P, Q in the last but one row. They are fitting the same data near 34 amu. The 3 vertical bars that show the error intervals are huge. (The SAD values are in page 8, item 3.) * In the graph O they fit the data using the expected curve of H2S+ and get a SAD value of 4.7 * In the graph P they fit the data using the expected curve of H3P+ and get a SAD value of 4.7 (again) * In the graph Q they fit the data using the expected curve of of mix of H2S+ and H3P+ and get a SAD value of 4.0. It's expected that with a mix you get a lower SAD, but it's clear that the error bars are so huge and the 3 fits so similar, that it's not possible to distinguish which one is the correct one. It looks like another case of overfitting.

xyzzy21 6y ago

This was debunked already. The phosphine didn't include any other markers for life and there are natural sources that are far more likely to create it. In any case, what allows bacteria doesn't mean jack for humans.