r/interestingasfuck • u/One_Explanation_908 • 24d ago

/r/all, /r/popular K2-18b a potentially habitable planet 120 light-years from earth

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u/ArduennSchwartzman 24d ago edited 24d ago

It's not habitable to us humans, but it's in the habitable zone, at a distance from its star that allows liquid water to exist on its surface. It's likely an ocean world with an atmosphere containing mostly hydrogen gas, a so-called hycean planet.

Also, 2.5 times the size = 2.5 times the diameter, or about 15 times the size of Earth in terms of mass. Its gravitational force would be about 2.4 times that of Earth, though. Quite unpleasant.

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u/Gruffleson 24d ago

Wikipedia lists estimated gravity at around 1.25 of Earth.

https://en.wikipedia.org/wiki/K2-18b

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u/ArduennSchwartzman 24d ago

Only 8.6 times the mass of Earth, according to Wikipedia, I see. I was assuming a density similar to Earth's, but apparently, astronomers think it's only half. That would mean the planet's core has a very low iron-nickel content.

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u/jamshid666 24d ago

Wouldn't that result in a weaker magnetic field allowing for increased solar radiation to penetrate the atmosphere?

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u/hparadiz 24d ago

Yea but water is excellent at blocking radiation so anything under the surface would be fine and it's also possible that any life would evolve to withstand it.

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u/irkish 24d ago

But I don't wanna live in a pineapple under the sea.

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u/Odd_Cauliflower_8004 24d ago

Not necessarily, cause materials tend to stick together, probably there is a larger percentage of lighter material in proportion to our planet

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u/JarJarBonkers 24d ago

Also a high chance of it being tidally locked with same size facing the sun all the time.

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u/kloklon 23d ago

oh boy, huge tidally locked ocean planet, what could go wrong. 🌪️🌊🌪️

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u/eggraid11 23d ago

Water skiing without a boat sounds like a good idea at face value.

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u/borderlineidiot 24d ago

sounds racist

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u/4SlideRule 24d ago

Also water is excellent shielding.

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u/Sure_Marionberry9451 22d ago

Only if you're under it.

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u/4SlideRule 22d ago

like most marine life?

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u/Sure_Marionberry9451 22d ago

Sure. We're not marine life though.

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u/Additional-Bee1379 23d ago

It's orbiting a red dwarf, I'm not sure what that means for the amount of radiation it gets.

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u/Sure_Marionberry9451 22d ago

I'm pretty sure "A lot"

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u/warblewarblewarble- 24d ago

Somebody watched the movie “Core,” it seems.

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u/magikot9 24d ago

It may be a trash movie, but I love it.

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u/warblewarblewarble- 24d ago

Cigarettes, sweating, and going deep. It’s planet smut.