Originally Posted by DJ The Kid

And false, 6x mass does NOT mean 6 times gravity.


The radius is indeed proportional to the cube root of the mass so if r = r_earth * M^(1/3). Then, g will be g_earth * M / (M^(1/3))^2 = g_earth*M^(1/3) and everyone will be 1.91 times heavier.

This weight wouldn't be very crippling, you should still be able to walk for an hour or so. ROFL

If Gliese 581d has the same composition as earth it would be compressed a bit more however