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[Trekkin]

The big problem with anything Cytherean is hydrogen and therefore water. Carbon-based life really cannot survive without C-H and O-H bonds, and it's not something that we can evolve away. CRISPR, not being magic, is of very little help.

And before anyone brings up fissioning heavy atoms into protons...the energy requirements are prohibitive sans technologies that would render Venus irrelevant.

[Karnewarrior]

We can't evolve away our biology, but that doesn't mean that the bacteria can't evolve a system where the nutrients for those bonds are sourced from somewhere else, like life on the seafloor depending on dead microbes from the surface.

I could see sets of extremophilic bacteria on the surface of Venus feeding off of dead life from higher in the atmopshere, where the pressure and temprature aren't so silly. If there's enough life up there, it could start to absorb more sunlight and cool the planet too. Earth wasn't super habitable when life formed here you know.

[Gentlefish]

Terraforming with railguns.

This is the wrong thread for railgun discussions

[Trekkin]

We can't evolve away our biology, but that doesn't mean that the bacteria can't evolve a system where the nutrients for those bonds are sourced from somewhere else, like life on the seafloor depending on dead microbes from the surface.

I could see sets of extremophilic bacteria on the surface of Venus feeding off of dead life from higher in the atmopshere, where the pressure and temprature aren't so silly. If there's enough life up there, it could start to absorb more sunlight and cool the planet too. Earth wasn't super habitable when life formed here you know.

That is exactly what it means, unless you're seriously proposing biological particle accelerators. If the hydrogen is not there, it is not there. The "nutrients" for hydrogen bonds include, inevitably, hydrogen, and there's very little of that on Venus either free or bound to anything and no way to extract it from anything else chemically. There's not actually enough sulfuric acid on Venus, in that sense. You can't have detritivores on the surface eating hydrogen captured by airborne microbiota when there's no hydrogen in the atmosphere for them to eat in the first place.

Pressure and temperature are solvable problems, yes, but missing elements really aren't.

[Egan_BW]

Terraforming with railguns.

This is the wrong thread for railgun discussions

railgun and science are not fundamentally opposed methods of thinking

[Reelya]

Pressure and temperature are solvable problems, yes, but missing elements really aren't.

Yup, serious lack of hydrogen there, most likely due to Venus lacking a magnetic field. Hydrogen is light, so it rises, and impacts from the solar wind scrubbed that stuff right out of Venus's atmosphere.

One nice idea is for a solar shade. The problem with that is that is that it'd act like a light sail and be pushed away from the sun. However, there's a proposal for a slatted reflective shade, and the strips reflect the sunlight onto the back of the strip next to it, equalizing the light pressure on each side. That would deflect the sunlight a few degrees away from Venus, but also reduce the solar wind particles. Otherwise hydrogen/water you add to Venus' atmosphere will just get stripped away again.

[Starver]

Or position it at slightly sunward of L1, but at the same angular orbital displacement, using (the average of a probably varying) solar pressure to keep up the orbital defecit.

If you insist on the equalisation technique, you need to do it in alternating directions, or else:

[WillowLuman]

I don't think it's ethical to terraform a planet unless you can establish it's lifeless. We can't fairly assume all life would have the same biochemistry as life on Earth. We're operating on a very poor sample size here.

[Starver]

We don't want to get the Treens mad at us, certainly. (Or the Therons!)

[Dorsidwarf]

I don't think it's ethical to terraform a planet unless you can establish it's lifeless. We can't fairly assume all life would have the same biochemistry as life on Earth. We're operating on a very poor sample size here.

I think it’s fairly easy to rule out a lot of planets as lifeless based on conditions, unless you subscribe to ideas like “living fully gaseous being in the atmosphere of star” fantasies that don’t even bother to propose a posible mechanism by which they could exist. Bacteria surviving from Mars’ wetter period living in subsurface icy water flows? Sure. Methane-based supercold life forms on Titan where it’s abdunantly available in liquid form? Sure. But all too often “life but nooot as we knooow iiit woOoOoo” is invoked to sidestep the fact that there’s no actual way for anything recognisable as life to form.

[Starver]

In any situation where we say "I bet we could send some of Earth's extremophiles to that other environment, and see if it can adapt to it" is, by definition, a place where Life As We Know It might already be found if we look hard enough. If it isn't independently arisen (maybe not predominantly in the Earth-Extreme places that we imagine it be, but in other places that might be harder to check but adjacent to them) then perhaps it has been already sent there via the extreme measure of hitching a ride on interplanetarily-transferrred impact debris (a provable thing, and may have happened a lot so the dice have been rolled plemty of times for at least one successful hitchhike ride and arrival).

Inoculating a 'dead' world could be deemed an attack, philosophically. The saving grace being that surely any 'native' organisms will by now have become better at dealing with local extremes than our kludged-together (or manually re-designed) seeding ones could ever be, this side of the biogenomic mastery needed to become the Progenitor race for some future's weirdly coherent galaxy-wide Panspermia origins.

Still, it messes things up. And as there doubtless is Life, But Not As We Know It (in as yet unknowable ways until we find at least one of the 'other answers' to The Meaning Of Life), at some point a messily incomplete survey that reveals no DNA/etc but overlooks <insert currently unknown alternative here> is going to allow us to do something we might regret later.

(Current biosecurity efforts might have already insufficiently sterilised our interplanetary probes. It is not even beyond contemplationnthat our attempts to avoid contaminating the moons of Jupiter/Saturn by sending our probes into the Jovian/Cronian atmospheres could have actually inadvertently sent a declaration of war against the respective Blimp-Creature civilisations therein! Yeah, protect the theoretical liquid-water life, but feel free to discriminate against the more dissimilar forms of life-organised matter! And these are beings who might, othewise, even be valuable allies in the future war against the coronal magnetodynamic beings who some day will organise deadly solar flares directly, deliberately and continually against us because of some other perceived slight or (on their part) rampantly nihilistic xenophobia! At least until the next bigger threat, like the Black-Hole Flingers/etc.)

[WillowLuman]

I don't think it's ethical to terraform a planet unless you can establish it's lifeless. We can't fairly assume all life would have the same biochemistry as life on Earth. We're operating on a very poor sample size here.

I think it’s fairly easy to rule out a lot of planets as lifeless based on conditions, unless you subscribe to ideas like “living fully gaseous being in the atmosphere of star” fantasies that don’t even bother to propose a posible mechanism by which they could exist. Bacteria surviving from Mars’ wetter period living in subsurface icy water flows? Sure. Methane-based supercold life forms on Titan where it’s abdunantly available in liquid form? Sure. But all too often “life but nooot as we knooow iiit woOoOoo” is invoked to sidestep the fact that there’s no actual way for anything recognisable as life to form.

But while lacking in hydrogen, Venus does have other volatiles. And given how little we've explored the solar system, it's a bit early to rule it out.

[Trekkin]

Doesn't Venus have a decent amount of hydrogen (obviously nowhere near as much as Earth, what with our oceans and shit) bound in heavier molecules such as sulphuric acid?

In absolute terms, yes, it does, but what matters is concentration; Cytherean clouds are very dry compared to ours. If we lump together the H2O and H2SO4, the total concentration is still less than 20 ppm. Earth's atmosphere rarely goes below 10,000 ppm even in cold deserts.

Not only would hypothetical Cytherean life need to lose much less water than life on Earth, they'd also need to get their water purely by breathing it, since there's no liquid water for them to drink. The membrane surface area required to do that will almost certainly necessarily lose more water to simple diffusion than it will gain, although I'll try to put numbers on that if you want.

There's enough for aerostats, perhaps, but nothing that needs to breathe.

[Hanslanda]

Some sort of extreme desiccant-type organism, a huge floating sail of those little packets we put in beef jerky, sucking hydrogen and oxygen out of clouds of acid and synthesizing H2O out of it to survive.


We have extremophiles that don't require oxygen or water to survive don't we? I need to look that one up.

[Trekkin]

Some sort of extreme desiccant-type organism, a huge floating sail of those little packets we put in beef jerky, sucking hydrogen and oxygen out of clouds of acid and synthesizing H2O out of it to survive.


We have extremophiles that don't require oxygen or water to survive don't we? I need to look that one up.

There are, but you'd need a thermoxerophile that doesn't respond to low water with dormancy -- and bear in mind that most xerophilic fungus like Wallemia and Trichosporonoides species that do grow dry still need a considerable water activity. They'll grow in things like dried sausage, but dried sausage is much wetter than Venus.

EDIT: Spelling, also I forgot to mention Zygosaccharomyces...which still needs, in the case of Zygosaccharomyces rouxii, a water activity of 0.62.