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.
The scary thing about the rare earth hypothesis is, that if we fuck it up, that might be it for the prospect of an intelligent space fairing species exploring the universe
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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.