My initial post was related to more of bacteria or organisms on space suits or moon walks and then flown back to earth in the comfort of a shuttle.
In: Biology
It is my understanding that the harder a creature leans, evolutionarily, into defense; the less it has to attack with. Look at a turtle. They have a slow metabolism, not really good range of motion, barely any claws, and most of them dont have a particularly good bite. But they have that shell. Very few things in nature can successfully penetrate an adult turtles shell. But as a consequence of growing that shell they have nothing left over to fight with. A turtle isnt taking down a shark any time soon.
Or look at a cheetah. Very very fast and deadly. But they are incredibly fragile compared to any other big cats. They put all their points into speed and attack, none in defense.
So a tardigrade has all its evolution points in defense. It can survive almost anything. But it also barely kills anything. They mostly prey on each other I think.
That’s not to say there couldnt be some space bacteria that is incredibly survivable that could be brought back to earth. But chances are likely if that happened it wouldnt be able to survive an oxygen rich environment. Or water. Or the bacteria in our bodies. Speccing into space survival would potentially mean you have no planetary survival adaptations.
There are real earth viruses that are very hard to kill. Like HIV. It has a hard protein shell that protects it from vaccines. But break that shell and our immune system easily kills it. The challenge is breaking enough shells of enough HIV virus bodies to offset the speed they breed.
These responses are way more involved than I usually think lol.That’s one of the reasons why we need intelligence running our world,not what we have now
Tardigrades can basically hibernate in extreme conditions, but they cannot be active or reproduce. Many of the creatures that can ‘survive’ do this as well, as spores or some such. They would fail to thrive on Mars.
fun fact, there is a group of people who believe that some viral outbreaks [could have been introduced to the earth from a meteor.](https://www.dailymail.co.uk/sciencetech/article-8104085/Scientist-claimed-coronavirus-came-SPACE-says-prevailing-winds-spreading-disease.html) im guessing if we actually had proof of extra terrestrial life we would do more to isolate samples/people coming in.
They can be killed and it is kind of easy for people in big space agencies:
[https://www.google.com/search?q=can+tardigrades+be+killed&rlz=1C1CHBF_enIN926IN926&oq=can+tardigrade+be+k&aqs=chrome.1.69i57j0i13i457j69i60.9467j0j7&sourceid=chrome&ie=UTF-8](https://www.google.com/search?q=can+tardigrades+be+killed&rlz=1C1CHBF_enIN926IN926&oq=can+tardigrade+be+k&aqs=chrome.1.69i57j0i13i457j69i60.9467j0j7&sourceid=chrome&ie=UTF-8)
Alright that’s a terrifying thought. Astronauts returning to space, decontaminating and all, just to find out something came back with them. *Shivers*
There was actually a mission that accidentally dumped tardigrades on the moon, kinda interesting https://www.wired.com/story/a-crashed-israeli-lunar-lander-spilled-tardigrades-on-the-moon/
I read a book about precision and it discussed this a bit. It said that basically we know there is bacteria in space on other planets like Mars because we put it there. The rigorous sterilizing efforts done to spacecraft preflight ensured that only the hardiest of bacteria survived, bacteria that could survive space. (If I am out to lunch please correct me if I am wrong, I am referencing a paragraph in a book I read like five years ago).
They can *survive* there but they cannot thrive. They don’t have any food, they cannot replicate, grow, or do anything else that’s necessary for long-term living. They just survive in a hibernation-like state.
So far nothing returned to Earth from a place that might have life. If a tardigrade from Earth catches a ride to space and somehow survives re-entry then it had a really hard time just to go from e.g. Florida to the Atlantic Ocean near Florida, or from somewhere in Kazakhstan to somewhere in Russia, or whatever. No harm done here.
If we return samples from Mars then things will get much more difficult. The samples need to be put into a capsule that then enters Earth’s atmosphere. The outer surface will be sterilized by the intense heat of the re-entry, but inside you still have the protected samples. You want to make *really* sure that the capsule doesn’t break open by accident.
Let’s say a bunch of space bacteria *does* make it down to Earth and lands in a nice fertile bog or something.
It’s going to have absolutely no resistance to the natural antibiotics of the first fungus that shows up. Failing that, it’s going to have no defense against the first virus that decides to move in. And god help this bacteria if it somehow gets into something with an immune system, having no way to hide and no survival strategy.
Simple life used to barely hanging on in some lifeless world is going to have no chance here.
Generally, the more prevalent life is somewhere, the meaner it is. We’re actually way more worried about the reverse happening, some Earth bacteria getting into Martian water on a probe and devastating whatever shred of biodiversity is there.
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