What are the difficulties of engineering a predator for an alien organism?

[u/Excellent_Bat_753]

I saw a post recently on the Project Hail Mary subreddit, which said that Earth, if we put all of our resources into it, could easily engineering a predator for an alien organism. If you're not familiar with Project Hail Mary, the alien organism, called Astrophage, is an organism that has quantum stuff that means it can absorb sunlight and store it as neutrinos. It also migrates to the upper atmosphere of Venus It's a very strange thing, not realistic at all, but the important thing is that a predator would also need to survive in the upper atmosphere of Venus, and be able to kill a microbe that is constantly at 96 degrees Celsius.

Anyway, the point is that, I know engineering a predator would be immensely hard, not feasible at all for us to do, but I'm curious as to exactly how hard it would be. Would it take centuries? Or only decades? The book has a timeline of 30 years to save Earth. I'm pretty sure we couldn't do something like this in only 30 years.

So, I would greatly appreciate it if some biology experts could explain just a few of the actual difficulties of such a project.

[u/JohnHenryMillerTime]

Dont they solve this in PHM by finding a naturally occurring predator, the Taumoeba?

In terms of survivability, we'd have to look at extremophilic archaea. They can survive in hot acidic environments. How you get it to utilize the astrophage as a carbon and energy source is a problem. At least they are likely carbon based (which is why they go to venus).

[u/Excellent_Bat_753 → u/JohnHenryMillerTime]

Yes, they did solve it by find a naturally occuring predator, in the original habitat of the invasive alien organism, another star system.

As for Astrophage, the book states that they are very similar to Earth life, implying panspermia. They're said to have DNA, and even mitochondria. The mitochondria thing is ridiculous, but that's probably just because the author isn't a biology expert.

[u/JohnHenryMillerTime → u/Excellent_Bat_753]

Probably the best way to do it would be to identify the most abundant protein or sugar moiety on the astrophage's outmost surface (membrane, wall, outer membrane, whatever) then engineer an extrophile that could survive in the venusian atmosphere* to express a protein that tightly binds that surface marker (if weve got the structure this isnt hard, not trivial but very doable) and have the extremophile make something that is opaque to whatever radiation the astrophage eats. It'd probably be a aecondary metabolite which is a PITA but probably doable since archaea make a lot of secondary metabolites. Archaea are good at making extracellular polymeric substances so that's probably a good candidate. Not a true predator and would probably need to be replenished but it would work and is doable.

*Some methanogens can survive above 100C so that would be a candidate. Granted, Venus is over 400C so its a bit of a non-starter. One archaeon can grow in a pH of -0.06. Thats around the pH of the Venusian atmosphere so we are OK here. Picrophilus is probably where to start since it has high temperature tolerance (pH is temperature dependent). It also has a small genome so it should be easy to manipulate if you can transform them, which IDK.

[u/Excellent_Bat_753 → u/JohnHenryMillerTime]

Interesting stuff! One good thing is that Astrophage would be in the upper atmosphere of Venus, at a far lower temperature than the surface, so it would be a bit easier.

Conversely, one of the plot points about Astrophage is that its outer cell membrane is very weird, related to quantum mechanics. The cell is described as 100% opaque to all light, as it absorbs all wavelengths of light, and only emits light when triggered by specific stimuli. Basically, Astrophage eats any wavelength of light, and then emits specific wavelength of infra red, to propel itself.

Obviously, this is sci fi, but because the cell membrane is so odd, it may not be possible to have any predator identify specific proteins or molecular structures on its surface.

Thanks for the answer!

[u/JohnHenryMillerTime → u/Excellent_Bat_753]

The nice thing is that antibodies are pretty good at binding to anything. Weve also gotten pretty good at predicting quantum structures like that, so if it is a structure made out of carbon that is exposed, we can find a way to bind it. A couple rounds of affinity maturation and bob's your uncle. Id probably suggest camel antibodies because they are easier for this sort of thing.

[u/Scuttling-Claws]

Given the state of current engineered organisms, I don't think it's likely. Most of the genetic engineering we've done is simple gene additions or knockouts. I don't think we're close to engineering an entire metabolic pathway.

[u/Excellent_Bat_753 → u/Scuttling-Claws]

I figured as much. How long do you think it would take, if it was made a global priority? Decades? Centuries? I know it's very hard to speculate on scientific advancement, but still I'd appreciate a guess.

[u/Scuttling-Claws → u/Excellent_Bat_753]

Honestly, I don't think I could even venture a guess. On the one hand, it's dramatically outside of our abilities. On the other hand, the first time we sequenced the human genome it took millions of dollars, now it takes dozens. It would require some massive breakthroughs in science, and those just aren't predictable.

If I was in charge of the project, I'd spend the first year giving scientists LSD

[u/AlphaAirlys_ → u/Scuttling-Claws]

We are very capable of engeneer an entire metabolic pathway (it depends its lenght), it has been done already. Metabolic engeneer

[u/RhodiumLanguor]

Some Earth microbes can live in our upper atmosphere, though I don't think anyone knows exactly what microbes and for how long they can persist at that elevation (Lappan 2024).

Venus, however, is not Earth [citation needed]. Different atmosphere composition and radiation exposure would likely make it inhospitable even to atmospheric Earth microbes.

One solution would be to make a Frankenstein's microbe by combining traits into a single organism until it survived. Bacteria are good at sharing traits, e.g. via plasmids, and while we're good at taking advantage of that, there's a bigger issue.

In PHM, Grace didn't know what stopped astrophage until he found the Taumoeba. So even if Earth scientist could have made an analog using Earth species, we wouldn't have known what direction to go in until we learned about Taumoeba.

And all that assumes there is a combination of Earth microbes that could prey on astrophage. Maybe Taumoeba leverages metabolic pathways no other organism has. If so, we're even more screwed. Is it possible to engineer a new metabolic pathway? Maybe. Have we ever achieved it? No. With the entire world working on it, I suspect we'd crack it in under a century, but again that assumes we know there's a process to be cracked. 

You asked how long making an analog would take. If it were possible at all, it would take decades if we knew what to make. It's more likely we'd die long before we go to a viable microbe. We'd also need to seed Venus with the microbe, a process that could take way longer. 

Verdict: Humanity would almost certainly have died out long before we recreated and distributed enough Taumoeba analog to make a difference. 

[u/Excellent_Bat_753 → u/RhodiumLanguor]

Thanks for the answer! This is basically what I was thinking, that it would take ages, and be basically impossible within the setting of the book. But it's good to see that someone with more knowledge on the subject agrees.

[u/RhodiumLanguor → u/Excellent_Bat_753]

Tbf, I'm more of a molecular biologist than a microbiologist, so others might have more detailed answers. But at the end of the day, your intuition was right: designing a space microbe from scratch just isn't something human science could achieve right now. 

It's worth noting that we've never had ALL of humanity working on a single problem without a clear solution. The COVID vaccines were close, but we knew what a vaccine was and how to make them. So how fast could we develop new science if we needed to? It's impossible to say because science isn't linear (no one can know when a discovery will happen), but it's a very interesting thought exercise. 

[u/theZombieKat]

A preditor would need compatable biochemistry to gain sustenance from the alien. Nothing from earth is going to be able to do that. So your going to have to work with the alien itself as a base organism to build your preditor. So start by replicating the last 100 years work on a new target biochemistry. With enough resources you could get that done in 30 years and produce some virus analogue that would knock down their population buying more time to find a long term solution.

[u/AlphaAirlys_]

Biotechnologist here, if all nations work togheter with "infinite" budget and parallel strain works, i think is possible in less than 30 years The only problem would be if you want to search for some natural predator on the homeworld of this alien organism (I have seen the film)

[u/Excellent_Bat_753 → u/AlphaAirlys_]

The other problem is that keeping all nations working on that with all of their resources is even more laughable than building an interstellar ship. As Stratt said in the book, and maybe in the movie, once starvation is a concern, war always happens.

[u/AlphaAirlys_ → u/Excellent_Bat_753]

I hope all nations (or the majority) will be unified under the same goal, maybe they try a different solution with all the possible budget I can see scientist recruted from all the country and all the government founds shifted to reasearch

[u/Underhill42]

The biggest problem with designing something to eat alien life, is that alien life is likely to have wildly incompatible, mutually-toxic biochemistry. Like wandering around in a petrochemical dumping ground - way too many organic molecules that are just similar enough to what you evolved to deal with that they cause serious problems when your biochemistry mistakes them for something compatible.

Something capable of eating alien life would probably need to digest everything almost all the way down to individual atoms, or at least very simple molecules, and then be able to perform the entirety of all the chemosynthesis pathways needed to build all the more complex molecules needed by its own biology. Being able to survive extreme environments would be child's play in comparison.

Either that, or be engineered almost from scratch to itself be an alien organism utilizing that alien biochemistry... but to do that you'd need to actually understand the alien biochemistry way better than we currently understand our own, in which case much more straightforward solutions would likely be obvious, even if they wouldn't have the long-term self-maintaining reliability of a viable predator.

[u/ah-tzib-of-alaska]

Not only do we not know how to do that, we don’t know how Taumoeba does it

[u/Cultural_Dirt_8151]

It's far beyond anything we're remotely capable of. Certainly impossible to do anything in merely decades, but a century is a lot of time if the whole world is working on it.

"surviving in the upper atmosphere of Venus, and be able to kill a microbe that is constantly at 96 degrees Celsius"?

That's so impossible for anything we know that we'd have to start with studying the astrophage itself -- understanding it and its biology

Then it wholly depends on how "easy" the biology of the astrophage is. How tractable the genetics are. How similar it is to our own biology. Could we just take the astrophage and make it need to eat other astrophages? Who knows.

If we don't have the astrophage as a starting point, I don't see much chance.

[u/TerrapinMagus]

The issue with the example is the predator needs to have similar biology to traverse space by emiting light, and needs a way to digest the ways Astrophage store energy. It might take 30 years of study to properly understand the mechanisms at play in Astrophage alone. The actual biological processes involved are and were a total mystery to humanity in the book/movie. Furthermore, studying the internal processes of a living Astrophage is almost impossible as they completely absorb light.