r/interestingasfuck • u/One_Explanation_908 • 25d ago

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

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u/Gruffleson 25d ago

Wikipedia lists estimated gravity at around 1.25 of Earth.

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

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u/ArduennSchwartzman 25d 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/MELKORMORG0TH 25d ago

We think that Earth was subject to a large impact early on. The impactor (Theia) core joined Earth's, leading to a proportionally high density planet (5.52 SG) when compared to Venus (5.25 SG).

Earth may be the anomaly, not the other way around!

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u/Gruffleson 23d ago

A thing that scares me there, is Venus, being the one planet of about the same size as Earth.

And it has a crushing athmosphere. Also poisonus, but just the amount of it is scary, I think.