| You're not the only thing that weighs twice as much; everything else does too. I would imagine the atmospheric pressure would be the most noticeable consequence of this. The article notes that the planet is substantially larger: > K2-18b is very unlike our home world: It’s more than eight times the mass of Earth, which means it’s either an icy giant like Neptune or a rocky world with a thick, hydrogen-rich atmosphere. And the Wikipedia article for "Super-Earth" mentions something relevant: > a planet with 2 Earth-radii and 5 Earth-masses with a mean Earth-like core composition would imply that 1/200 of its mass would be in a H/He envelope, with an atmospheric pressure near to 2.0 GPa or 20,000 bar For comparison, the atmosphere on Earth (sea level) is approximately 1 bar. It looks like the apparent atmospheric pressure on such a planet might be similar to being approximately 200 kilometers below the surface of the ocean on Earth. For additional perspective, the Mariana trench is (I believe) the lowest point on the planet, and is only like 11 kilometers deep. So I guess what I'm saying, is that the apparent doubling of one's weight would be an insignificant concern in the grand scheme of things. |