Question

What if Earth were the size of Jupiter? What would be different about life as we know it?

Answer 1

Increased gravity for one thing...

Explanation:

Jupiter is roughly `11` times the diameter of the Earth, so has volume about `1300` times the volume of the Earth.

If the Earth were the size of Jupiter but still the same density as it is now, then gravity would be `11` times stronger at the surface (being proportional to the mass divided by the square of the radius), which would make it a little difficult for vertebrates similar to us to function - Imagine trying to carry your own weight plus `10` times that.

The atmosphere would probably be considerably denser as a result of the increased gravity. I am not sure whether that would tend to increase or decrease the temperature at the surface. Would it reflect more of the sun's energy back into space before it reached the ground or would it generate a stronger greenhouse effect? If the latter then the surface could be considerably warmer than we experience.