But I have hard time believing even hardened organisms like moss or tardigrades could survive millions of years of hard vacuum and extreme cosmic radiation. Maybe embedded in some properly protective envelope, 1 out of billion trillion might. And then that one has 1 out of billion billion trillion chance to land eventually on a place that could be called livable. Or add few extra zeroes.
In genetal, nature works with small chances, look how many seeds a plant gives and how few of them will be a new plant.
(Or how many sperms are created for 1 human)
But sure, chances here are way, way lower.
(And terrorism is often more about causing fear than raw death counts.)
When you come to some place and change it drastically, is it a good thing or a bad thing? I don't think it is. There are some excuses that I can accept, but if you do it "just for fun" of it, I think it is an evil deed.
Places have their own history, their own shapes and forms, and then someone comes and wipes it off just because they can. It cannot be Good, can't it?
Sending spores to a planet that already has life might work. But I can’t help but think whatever life we introduce would be at a disadvantage. Maybe life on that planet never incorporated certain proteins, vitamins, or amino acids and whatever we send just ends up getting scurvy and dies out.
* I am aware of various experiments that did attempt to raise animals in perfectly sterile environments, where they died, but the only way to sterilise and maintain sterility, are extream, and largely impossible while keeping any single lifeform, alive.ie: it is far from the default
A community of several different kinds of bacteria would have better chances than a single species, but for bacteria there is certainly no need for thousands of species.
Autotrophic bacteria would need only an environment providing less than 20 essential chemical elements (most of which belong to the most abundant elements, a notable exception being molybdenum) and either solar light for energy, neither too little nor too much, or a chemical source of energy, like dihydrogen + carbon dioxide, which can be provided by volcanic gases or by the reaction of water with volcanic rocks.
There would have been many places in the Solar System suitable for bacteria, except that where there is water, it is usually too cold, and where it is not too cold, there is no water.
Moss has already adapted to barren environments. Its niche is growing where nothing else grows. Like, on top of rock. It's not having roots, not mingling with modern temptations in the soil. Most mosses actually aren't doing well in competitive, complex ecosystems full of nutrients and such.
Being a larger mass just means an object will take longer to heat up.
I don't know if it is significant, but tidal sources of heat might not scale the same either.
The Earth's internal radioactivity is a miniscule energy source compared to the sun.
At least during emergence of life there was the faint young sun + higher proportions of radioactive elements, so could have made up 0.2% of outgoing thermal radiation or so on earth (ignoring outflow of residual heat from early collisions). I think 5-10 earth masses is the limit for terrestrial planets, and you can imagine having say 10x more radioactive elements and still hospitable to life, rather than being made of solid uranium. So maybe double digit percentage radiant heat outflow differences between very small and very large on those.
Also it would need many more plants than animals. I would rather go with an aquarium.
You can fit more into a larger terrarium, but that doesn't require a larger terrarium to contain more. Regardless of what is contained within the terrarium, it's heat production is limited by what it receives from the environment.
> But greater atmospheric depth probably still increases equilibrium temperature by reducing heat transfer through that side of the terrarium.
Greater atmospheric depth affects heat transfer by changing the density of the atmosphere, which is relevant for an atmosphere held to a body by gravity, but not for one contained in a pressurized vessel like a terrarium. A terrarium with a 1 atm internal pressure has an atmosphere depth equal to earth's atmosphere regardless of size (at least up until the point where the terrarium's gravity is comparable to a planet).
Go make a pile of mulch and monitor the temperature at the center. You will find that after a while it is hotter than ambient by a large margin because it is generating heat. The more mulch you permit to decay, the more heat will be generated.
>Greater atmospheric depth affects heat transfer by changing the density of the atmosphere
Greater atmospheric depth affects heat transfer by increasing the chances that an outbound photon of black body radiation hits a molecule that will absorb it and later re-emit the energy as black body radiation in a random direction, only sometimes still in a direction that will escape. It’s true that increasing atmospheric density will increase the chances of an outbound photon being absorbed, but so will increasing the distance the photon has to travel through atmosphere of any given density. The deeper the bubble of air, the more re-absorption.
>A Martian meteorite is a rock that formed on Mars, was ejected from the planet by an impact event, and traversed interplanetary space before landing on Earth as a meteorite.
I always thought this was peak exo-earth evolution though:
r721•2mo ago
adrian_b•2mo ago
https://www.cell.com/iscience/fulltext/S2589-0042(25)02088-7
The link provided in The Guardian is broken.