14

Why not bring cyanobacteria and fertilizer to the atmosphere of Venus to improve conditions for life there by producing oxygen ?

Planetary protection could be a reason. According to Wikipedia:

Planetary protection is a guiding principle in the design of an interplanetary mission, aiming to prevent biological contamination of both the target celestial body and the Earth in the case of a sample return mission.

The missions are categorized into 5 groups and Venus is classified into Category II, implying no requirements for bioburden reduction or sterilization of equipment, supposing that there is only a remote chance that contamination by terrestrial microorganisms could jeopardize future explorations.

Only a few scientists have speculated that thermoacidophilic extremophile microorganims might exist in the lower-temperature, acidic upper layers of the Venusian atmosphere. It has been speculated that the clouds there could contain chemicals that can initiate forms of biological activity, like sulfur allotropes, but it is very unlikely that there will be Venusian microorganisms that use water and carbon dioxide for their existence.

So the biosignatures for instance that the Venus Atmospheric Maneuverable Platform will look for will be very different from those from the introduced cyanobacteria and consequently they will not jeopardize the explorations of the existence of Venusian life in the cloud region.

Cyanobacteria are a group of photosynthetic bacteria who use the energy of light to synthesize organic compounds from carbon dioxide, producing oxygen this way.

Nostoc commune is a colonial species of cyanobacterium which forms a gelatinous mass with other colonies growing nearby and in some cells nitrogen-fixing occurs. It is able to survive in extreme conditions in polar regions and arid areas. The cells also contain pigments that absorb ultraviolet radiation, which enables it to survive high levels of it. A dessicated colony is resistant to heat and to repeated patterns of freezing and thawing.

Nostoc commune can also withstand acidic exposure

So it seems that Nostoc commune could be a good candidate for surviving the harsh conditions within the cloud layers if it could be supplied with the necessary trace elements. The sticky biofilms that it produces could be supported by a mattress-like shape made of silica aerogel to keep it buoyant and to supply it with those elements.

The fertilizer could be delivered mainly in the form of hydroxides like KOH, Ca(OH)2 and Mg(OH)2 that would react with the suluric acid in the clouds to form the required water and sulfates.

The big question would be if the biofilms could float themselves outside the supporting mattress, feeding on the droplets of water with fertilizer.

Summarized, the water used by the cyanobacteria will be recycled eventually and the produced oxygen will accumulate and CO$_2$ removed !

Could not one trip for cyanobacteria to the atmosphere of Venus be a giant leap for life ?

Cornelis
  • 7,535
  • 2
  • 26
  • 77
  • 5
    What's the upside to doing this? – zeta-band May 16 '18 at 17:32
  • How much fertilizer will be necessary to get an effective concentration over a region large enough to be observable from an orbiter? – Uwe May 16 '18 at 18:25
  • 2
    @zeta-band Jump start to terraforming – called2voyage May 16 '18 at 18:42
  • @called2voyage More like a proof of proof of concept than a start if it needs to live on inflated supports and imported fertilizer. –  May 16 '18 at 18:54
  • @notstoreboughtdirt No, it would be producing oxygen which would be useful to later life. – called2voyage May 16 '18 at 18:55
  • @Uwe I don't know. First it could be examined if this type of bacteria can survive at all and after that a lot of experimentation would be needed to expand – Cornelis May 16 '18 at 21:57
  • @zeta-band Wouldn't it be great if this bacteria could survive? And maybe it could adapt more and more by mutation. – Cornelis May 16 '18 at 22:07
  • @Uwe Probably a lot of fertilizer could be spoiled by the strong winds so a location near the poles would be preferable, – Cornelis May 16 '18 at 22:13
  • @notstoreboughtdirt Yes, it's far from ideal but one has to start somewhere. If you have ideas about this, please tell ! – Cornelis May 16 '18 at 22:23
  • I've added a 'big' question,@notstoreboughtdirt, which concerns your comment. – Cornelis May 17 '18 at 07:22
  • 1
    "Why is this a bad idea" seems to be opinion-based. I'm not sure if, in general, Stack Exchange is a good place to do even shallow technical reviews of proposals. That generally requires a kind of discussion that the question/answer format isn't good at. – Erin Anne May 18 '18 at 03:39
  • @ErinAnne Yes i think you're right. I've adapted this sentence somewhat. – Cornelis May 18 '18 at 07:56
  • There are hundreds of questions on Space Stack Exchange starting with 'Why not'. – Cornelis May 18 '18 at 12:16
  • 3
    "Why not?" is not a mission rationale.

    To get the government to spend billions of dollars on a project, you must supply the reason "why".

     – Organic Marble May 20 '18 at 14:07
  • @OrganicMarble Aren't the last two sentences of my story clear enough to state that turning CO2 into O2 is the goal ? And wouldn't thriving cyanobacteria in the atmosphere of Venus not be a milestone for life ? – Cornelis May 20 '18 at 15:05
  • 1
    Why should any government pay billions of dollars to achieve that? – Organic Marble May 20 '18 at 15:15
  • @OrganicMarble Thanks to your comments i've changed the question somewhat. – Cornelis May 21 '18 at 10:27
  • 2
    There is a Wikipedia article on this topic, which gives an overview of both possible approaches and problems. In particular, it notes a very similar idea suggested in 1961 by Carl Sagan and the reasons why his idea could not work. – Anthony X May 21 '18 at 18:56
  • @AnthonyX Good links. Two reasons i think, one the lack of hydrogen. So i proposed hydroxides, indeed a lot of them will be needed but water could be recycled, The other reason. Sagan supposed the organic molecules would form CO2 again. But before that, concentrated H2SO4 could turn those molecules into carbon and water! – Cornelis May 21 '18 at 21:37
  • 3
    I have to admit, my first thought when reading this is in the form of Ian Malcom: "Yeah, yeah, but your scientists were so preoccupied with whether or not they could that they didn't stop to think if they should." – Cort Ammon May 22 '18 at 00:25
  • Personally, I think we should just get handfuls of water-bears and a mini rail-gun. Then we should aim the bio-rail-gun at random planets during fly-by's and shoot the water-bears at the planets. – Magic Octopus Urn Oct 10 '18 at 14:36
  • 3
    I really, really wouldn't want to meet pathogens that developed to thrive in Venus conditions. – SF. Oct 16 '18 at 21:03
  • 1
    In regards to the close votes, I think that while 'technical proposal' type questions can be hard to answer and be prone to opinion-based answers, this question is fine. The main thrust of the question is a feasibility one, even though it isn't explicitly stated. It has received a solid answer. It would be of interest to people searching for atmospheric venus colonisation. – Ingolifs Oct 16 '18 at 21:49
  • 1
    It's entirely possible that life has already been brought to Venus, just not intentionally. More than one probe has entered the atmosphere of Venus; even if carefully sterilized during assembly/launch preparation, there is still the possibility that some terrestrial organisms could have hitched a ride, just unlikely to have survived. – Anthony X Jun 22 '19 at 22:25
  • Making oxygen? Isn't that actually a poison? We've adapted to it, but that's just Earth organisms. – Oscar Lanzi Oct 30 '19 at 11:52
  • @OscarLanzi Because it 's not a greenhouse gas, it would lower the temperature on Venus. – Cornelis Oct 30 '19 at 12:42
  • 1
    @Cornelisinspace not exactly related but in addition to the phosphine news there is some interesting background info https://phys.org/news/2020-09-phosphine-venus-clouds-big-life.html – uhoh Sep 20 '20 at 17:11

2 Answers2

18

Question: Why not bring cyanobacteria and fertilizer to the atmosphere of Venus to improve conditions for life there by producing oxygen ?

... Only a few scientists have speculated that thermoacidophilic extremophile microorganims might exist in the lower-temperature, acidic upper layers of the Venusian atmosphere. It has been speculated that the clouds there could contain chemicals that can initiate forms of biological activity, like sulfur allotropes, but it is very unlikely that there will be Venusian microorganisms that use water and carbon dioxide for their existence. ...

Comments: @notstoreboughtdirt No, it would be producing oxygen which would be useful to later life. – called2voyage♦ May 16 at 18:55

There is a carbon chauvinism (or if you prefer Star Trek: "The Devil in the Dark") aspect to this, that we would alter the conditions of Venus to our liking, at the expense of any existing life, and damage the existing conditions (life, or no) calling future exploration and measurements into doubt.

So there is the 'be nice' aspect.

Probably more important is the cost and usefulness of such actions. Let's simply say that the cost would be significant and that the money could go elsewhere, let's skip to the usefulness ...

Habitable Zone

Venus is exiting the habitable zone and Mars is within it. Terraforming of Venus is a lost cause, terraforming of Mars has a future purpose. It will take a long time to perform either action (terraform Venus or Mars) slowly (at a lower cost) so it makes sense to choose the location on the way in than to choose the location that has left the building.

As for alternative uses for funding destined for such purposes, it could be used to search for existing life on other bodies within habitable zones (plural).

Habitable Zones here and elsewhere

NASA has a project "Mars Ecopoiesis Test Bed" where phase one (Last Updated: Aug. 6, 2017) is completed. There's a .PDF report on that webpage that lists this rationale:

"Rationale

Ecopoiesis will require water. That means maximizing the chances of liquid-phase water being transiently present in the test bed with the most likely sites being found at Mars’ lowest altitudes and latitudes [Kuznetz, 2006]. A preliminary identification of these “landing” sites, already considered for certain past and future robots, is given briefly in Table 1. The tidal pressure swings of +0.5 mbar need to be considered. These sites are also thought to contain evaporites, possibly including nitrates (all of which are water soluble) to provide nitrogen and magnesium salts [Tosca, 2006]. Recent results from the Curiosity Rover in Gale Crater are encouraging with regard to the availability of minerals to support autotrophic life [Navarro-González, 2013]. The big question of course has to do with the thermodynamics and transport processes of water in real and simulated Martian environments. Even at 11 mbar, the vapor pressure of water is well below the 6.1-mbar triple point, where, at increased temperature ice will normally sublime. However, speculative calculations modeling the diffusion of water vapor from ice surfaces during sublimation indicate a local (within a few mm of ice) increase in water vapor concentration to some 60%, or the required 6.1 mbar in the 11 mbar environment [Levin and Weatherwax, 2004]. Therefore, early proposed research will use the Techshot simulator [N. Thomas, 2006] to test such hypotheses.".

They also have a webpage titled: "Planting an Ecosystem on Mars" (May 6, 2015). I can't find NASA's 'Terraforming Venus' webpage but the idea is unpopular on Quora: "Does NASA have any plans to terraform Venus?". On the other side of the coin Universe Today has an article favoring the idea: "How do we terraform Venus?".

Community
  • 1
Rob
  • 3,266
  • 1
  • 15
  • 36
  • 2
    If we have to be nice to life that we don't know, terraforming any potential planet would be impossible. – Cornelis May 21 '18 at 09:49
  • The costs can be brought down considerably , so i've changed the question somewhat. – Cornelis May 21 '18 at 11:51
  • Venus has not left the building ! – Cornelis May 21 '18 at 14:12
  • According to this article, the inner edge of the Habitable Zone can be as close as 0.48 AU around a solar-like star. – Cornelis May 21 '18 at 14:28
  • According to, "Towards the Minimum Inner Edge Distance of the Habitable Zone the minimum is listed on page 16: "• We estimate that the fundamental inner edge of the Habitable Zone can be as close as 0.38 AU around a solar-like star (within the orbit of Mercury), if the relative humidity of the planetary atmosphere is low (1%) and the surface albedo is large (0.8). If the surface albedo is moderate (0.2), the inner edge is at 0.59 AU for the same relative humidity. In both cases, we assume a surface pressure of 1 bar, and $10^{−4}$ CO2 mixing ratio. – Rob May 21 '18 at 16:45
  • Continued: "The inner edge of the habitable zone is pushed close to the host star if the greenhouse effect is reduced (low relative humidity) and the surface albedo is increased. We argue that if precipitation occurs predominantly in liquid form, the habitable region on the planet’s surface remains extended. The requirement for liquid precipitation provides a lower limit on relative humidity, which we estimate to be 1% for a wide range of surface temperatures and pressures." -- So if you're a desert dweller (cactus, scorpion, tumbleweed, etc.) it's OK, otherwise it's too hot. – Rob May 21 '18 at 16:51
  • Yes, that would be hard times for habitants at that time. So i'm interested in what can be done now . Would it be very damaging if a handful of bacteria will produce a few cubic km of oxygen in the uppercloud layer ? – Cornelis May 21 '18 at 17:12
  • I've updated the answer with the direction that NASA is currently pursuing. I can come back later with some more research and possibly make another edit addressing each point completely. – Rob May 21 '18 at 17:30
  • 1
    +1 for this: "As for alternative uses for funding destined for such purposes, it could be used to search for existing life on other bodies within habitable zones (plural)." – called2voyage May 21 '18 at 17:37
  • @Conelisinspace : "If we have to be nice to life that we don't know, terraforming any potential planet would be impossible. " That assumes that every possibly habitable planet is actually inhabit ed . If there is no habitation, then there is nothing to worry about destroying. This doesn't seem so likely for Venus, but would be more likely for Mars. We need to scope them out first before doing this, and determine for sure. If something is found, then we could think about what we need to do to preserve it or if that's possible, and if we can rule it out, then of course there is no obstacle. – The_Sympathizer Oct 10 '18 at 11:28
  • @The_Sympathizer I meant: If we have to be nice to forms of life that we don't know that could exist, then we couldn't introduce life on any other potential planet because of the potentail to destroy it. I don't understand why that assumes inhabitation of every planet – Cornelis Oct 10 '18 at 13:46
2

To date, while there are discussions and plans being formed with respect to terraforming, there has not been any serious plans to do so. And that isn't likely until we are able to start really exploring the Solar System with manned missions.

I suspect that this sounds like a good plan to start terraforming Venus, but it will take time to actually make it work. But for now, terraforming is for the far distant science or science fiction.

PearsonArtPhoto
  • 121,132
  • 22
  • 347
  • 614
  • 1
    Thank you for your answer, but my question is not about terraforming, but about starting life in the atmosphere of Venus. If that works, is up to the bacteria brought there. It should not take much time to explore with instruments if they will survive there. – Cornelis May 18 '18 at 15:50
  • The terraforming of Earth, the production of the oxygen in the atmosphere by plants took a very long time. If terraforming of other planets would be 10 times faster, it will be still a very long time. If mankind needs terraforming of other planets, would it be possible to wait that long for it? – Uwe May 18 '18 at 22:59
  • @Conelisinspace Terraforming means too make more like Earth. More oxygen, bringing life, etc, would be a form of terraforming. But yeah, if you can get something to remain floating, and live off of oxygen, CO2, N2, and sunlight, it should be able to survive on Venus. – PearsonArtPhoto May 19 '18 at 01:12
  • Terraforming of Venus would require a lower pressure and temperature of the lower atmosphere. – Uwe May 19 '18 at 10:20
  • @Uwe Bacteria have a huge multiplying capacity. The limiting factors are outside the cells, maybe radiation or pH at early Earth. Are there any other means for terraforming with such a potential ? – Cornelis May 19 '18 at 12:43
  • @Uwe So we have to start with the upper atmosphere and exchange CO2 with O2 and that will bring down the temperature. – Cornelis May 19 '18 at 12:48
  • 4
    @Conelisinspace If you want to transform Venus fast (and you're a somewhat more technologically advanced than us, but not in possession of new physics) you use a sunshade. A thin mirror roughly the size of Venus positioned between Venus and the Sun (held in place by balancing light pressure and gravity) would cool it enough to freeze out the CO2 in a few centuries – Steve Linton May 21 '18 at 11:30
  • @SteveLinton But what about the costs ? Andt this method would not make oxygen. I just would like to know if cyanobacteria could live in or just above the clouds, to start with. – Cornelis May 21 '18 at 12:02
  • There is actually a fair bit of oxygen in the atmosphere of Venus as it is, in the upper atmosphere. The atmosphere at 50-65 km is similar to that of Earths, to the point that if you could live in a flying platform of some kind that high up, you could probably breathe without assistance of a machine. – PearsonArtPhoto May 21 '18 at 13:36
  • @PearsonArtPhoto 20% oxygen ? Do you have a link ? – Cornelis May 21 '18 at 14:31
  • https://en.wikipedia.org/wiki/Atmosphere_of_Venus – PearsonArtPhoto May 21 '18 at 15:33
  • @PearsonArtPhoto You must be joking ! In that link i only find atomic oxygen in trace amounts ! – Cornelis May 21 '18 at 16:10
  • I was mistaken. It seems that a base full of breathable air could float, but the atmosphere would not support that breathable air. – PearsonArtPhoto May 21 '18 at 16:26
  • 1
    @Conelisinspace: Oxygen is the problem, though. If you somehow kept photosynthesis going while recycling the water, you would end up with an extremely toxic high-pressure O2 atmosphere and a surface carpeted with carbon powder, which will be highly explosive in that atmosphere. You need to import hydrogen to terraform Venus, to turn the excess oxygen into water and lock most of the atmosphere up as biomass. Lots of hydrogen...about 40 quadrillion metric tons. – Christopher James Huff Nov 10 '18 at 17:26
  • @ChristopherJamesHuff Yes, hydrogen is the problem but i think there's no practical answer to that. To get even 10 percent of oxygen would be great and will take a lot of time ! :) But wouldn't it be amazing to see that happen ? (for next generations) – Cornelis Nov 10 '18 at 22:28
  • 1
    @Conelisinspace: ...not really? Equipment on the surface will now have to worry about spontaneously combusting on top of the high temperature and pressure, not to mention all the carbon dust blowing around. At altitude, you've made the atmosphere far more corrosive, and no more habitable. Devoting the resources to colonizing Venus would be a lot more productive than giving it an even more hellish atmosphere. – Christopher James Huff Nov 10 '18 at 23:54
  • @ChristopherJamesHuff I agree with you about the surface, but at altitude 10% oxygen is still less than on Earth. What practical resources are you thinking of ? – Cornelis Nov 11 '18 at 13:36
  • 2
    At altitude 10% oxygen is more than enough to cause corrosion, especially in that carbon dioxide atmosphere full of sulfur dioxide and sulfuric acid, and it doesn't bring the atmosphere any closer to being breathable while the lower density means buoyant lift is less effective, making doing anything in the atmosphere more expensive. Practical resources: all the building material and mining equipment that goes into constructing and supplying all those algae farms, all the water collected, etc. You could build entire floating cities for less. – Christopher James Huff Nov 11 '18 at 13:55
  • @ChristopherJamesHuff I thought you meant hydrogen resources. Couldn't hydroxides from Earth be the most practical, also changing the acid to sulfates ? Would aerogels or zeolite be strong enough to collect water from the clouds ? – Cornelis Nov 11 '18 at 15:59
  • 1
    Ignoring the immense quantities of hydroxides that would be required, what would that accomplish? You simply can not do anything useful in terms of terraforming Venus without dealing with the 90 atmospheres of CO2. – Christopher James Huff Nov 11 '18 at 19:05
  • @ChristopherJamesHuff Ignoring the immense quantities, hydroxides with CO2 gives solid carbonate and H2O. Thanks, it's good to have exchange ! – Cornelis Nov 11 '18 at 22:53
  • 1
    40 quadrillion tons of H2 is a bit more achievable than 2 quintillion tons of LiOH, the lightest hydroxide. You're not sequestering the atmosphere of Venus with anything imported from Earth, not without de-terraforming Earth to do it. – Christopher James Huff Nov 12 '18 at 05:12
  • @ChristopherJamesHuff At least, with LiOH the sulfuric acid could be removed and a lot of H2O gained. – Cornelis Nov 12 '18 at 09:44
  • 1
    Except that's about a thousand times more lithium than exists in Earth's crust, never mind the impact of removing that much water from Earth. Even if you could get it, carpeting the planet in lithium carbonate is not a great start at terraforming it. Besides, Venus has plenty of minerals that will readily combine with the sulfuric acid and a good part of the CO2 if you just cool the place down and supply a lot of water. There is really no alternative to replacing the hydrogen that it's lost over time. – Christopher James Huff Nov 13 '18 at 22:34