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Is there any benefit to the planets being earth-sized? I would think the important part is that they're in the habitable zone.
by frgtpsswrdlame 9y ago
Is there any benefit to the planets being earth-sized? I would think the important part is that they're in the habitable zone.
- graphitezepp 9y agoAny hypothetical colonization effort would require substantially less adaptation if we don't have to worry about humans growing up in much different gravity.
- pilsetnieks 9y agoGravity. A rocky planet, roughly Earth-sized, will have about the same gravity as we have on Earth. Both larger and smaller planets will have a deleterious effect on human health, at least until we (our descendants) adapt (if it's even possible.)
- frgtpsswrdlame 9y agoAh silly me, how could I forget about that? <floats slowly away>
- kibwen 9y agoIf a planet is too small, it has a hard time retaining an atmosphere (see Mars) and a hard time sustaining the inner dynamo necessary for a magnetosphere (see Venus). For the latter, the fact that Earth is barely larger than Venus suggests that Earth might be very close to the lower bound of habitable terrestrial planet size. Bigger is better than smaller, but too big and you obviously stop being terrestrial, the atmosphere becomes too thick to breathe, the surface temperature gets too hot from pressure, and it might become impractical to escape the surface with standard rocketry due to increased gravity. I think I've read that double Earth's mass is somewhere around the suspected upper bound for reasonable human habitability.
- BurningFrog 9y agoI don't think it changes the possibility for life at all. It does make colonizing it seem less possible, but that's hardly a practical concern anytime soon.