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If you look at one of my previous questions, I ask about a tidally locked planet and it has come to my understanding that such a planet would be under a lot of radiation from the sun. So I’m curious if larger lifeforms could evolve to survive in such conditions if it were happening for billions of years. Specifically life that lives on the surface of the planet, not avoiding the radiation.

I am not an expert on different types of radiation but I know that in Chernobyl, life has managed to thrive within its radiation zone so could the same be theoretically possible but on a much larger, more intense scale? If so how would evolve to do so? Or would life barely be able to sustain itself in those conditions?

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I might be misunderstanding this, but...I looks like you might be using the word 'radiation' in two separate ways?

The radiation at Chernobyl is 'ionizing radiation'. It has high enough energy to kick out electrons from around their atoms. Therefore, it can interfere with biological molecules (like genetic material), which is what makes it dangerous.

On the other hand, solar radiation is, for the most part, non-ionizing. It might be very /intense/ (as in, turning the sun-side face of a tidally locked planet into a molten desert), but for the most part individual photons don't have high enough energy / frequency to mess with chemistry. The exception to this are high-energy UV rays (you could get plenty of those on a tidally locked planet, if you want) and X-Rays (events called solar flares prduce X-Rays, but I think having an atmosphere blocks it, and presumably you'd want an atmosphere). So you might easily enough have organisms that shrug off high-energy UV rays, but they won't survive Chernobyl. It might vary a bit depending on the star, but for the most part that's it, I think.

One exception to this is pulsars. Pulsars are what's often left of giant blue stars after they explode. They're very small, very dense stars (imagine neutrons piled to the size of a mountain). They...uh...emit ionizing radiation like nobody's business. Like, for a subset of them (called magnetars), you can detect their magnetic field from /halfway across the galaxy/! At that point, you don't need your planet to be tidally locked. It's going to be blasted with ionizing radiation either way.

Whatever life develops there...would be very, very strange. There'd be so many things to consider, such as the amount of light you got (probably not much, might need to supplement the warming of the planet with hydrothermal vents)...which I guess you might get around by having your planet in a binary system, with one of the stars being a pulsar...and I'm wondering if that would work because sometimes pulsars /blow nearby stars to bits/...but...yeah. Lots to think about.

I'm wondering if another solution might be to have a planet in a late-generation solar system. From the little I know, stars from from clouds of dust and gas called nebulas, exist for a while, then some of them explode and this forms other nebulas, then time passes and more stars form. However, as these generations of stars occur, the elements involved (in the formation of the star and the planet) get heavier and heavier. I remember reading in a sci-fi book that planets in later star generations might have too many heavy metals (like uranium, which has useful radioactive isotopes!) to be comfortable for humans. Can't attest to the accuracy of that. Then again, you don't need your planet to be tidally locked. You'll have a planet that's largely radioactive. And...maybe it would make sense placing it in a more central part of the galaxy, where more star generations would've occurred...but that's just a guess and would have to be checked.

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There are radiation-resistant organisms that can withstand high doses of radiation. Organisms with the highest levels of radioresistance are mostly microorganisms, but certain insects such as the fruit fly or cockroach can withstand high doses of radiation as well.

All of these organisms will eventually die from continuous high radiation.

But there are also some rare organisms that thrive on radiation.


Life on Earth is adapted to the situation on Earth. There aren't many places with high radiation on Earth, due to its atmosphere, so radioresistance or an ability to thrive on radiation are not a necessity on Earth and therefore not very developed here. But as the examples show, radioresistance is possible, and in a highly radiated environment organisms would certainly adapt to the radiation.

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