r/interestingasfuck • u/howimetyourcakeshop • 10h ago

Our moon being formed.

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u/ShaggyCan 10h ago edited 10h ago

Earth is a strange planet for this reason. Because Earth's core is so large in proportion to it's diameter it has a stronger magnetic field at the surface and is denser than a planet formed through normal gravitational accretion. If Earth was any lighter, it would have ended up like Mars, unable to hold it's atmosphere. Earth is probably at the very low end of habitability due to its size. Most exobiologists look at what we call super Earth's because they are more likely to have complex life. Another cool fact is that the further you go back in time the shorter the day lasted on Earth and the closer the moon was. 65 million years ago a day was around 23 to 23.5 hours long and the moon was 2 to 3 thousand km closer.

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u/daou0782 8h ago

And do you know there’s a very narrow window where planets have the right mass/density to allow for escape velocity?

So maybe larger worlds are more habitable but life on it is trapped in their gravity wells. And lighter planets don’t normally have cores large enough to allow for magnetic fields strong enough to protect their atmospheres.

Truly a rare earth.

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u/Ent3rpris3 5h ago

Sort of tangential, but would the increase in gravity mean a higher 'pressure' of the surface crust, thus the processes that allow for material to turn into oil would be affected?

Like...all other things being equal but dialing up Earth's surface gravity ~20%, could we expect there to be any different amount of oil, or maybe even diamonds or other things formed under pressure, compared to Earth as we know it today?