Question

Would it be (in theory) possible to physically walk on "gaseous" planets? (i.e: Jupiter, Saturn, Neptune, Uranus)

Consider gravity to be as strong as the Earth's.

Answer 1

In actuality, you would float, since the density of the gas becomes greater the deeper into the atmosphere you go. When the density of the gas became more than your body density, you would then float at that depth.

However, it is theorised, and there are observations that seem to indicate this, that the cores of the gas and ice giants, are rocky in nature 9with a mass of at least a few earths), so if one could weight themselves sufficiently (and protect themselves from the massive pressures at that depth), then you could walk upon that core, in much the same way you can walk upon the sea or ocean floor.

Answer 2

Would the surface be in a gaseous state? shouldn't it be in a solid or liquid state?

Answer 3

If you are referring to the rocky core then because of the great pressure from the above atmosphere it would most certainly be solid (according to the models anyway). If talking about the point where you would float, then it would be more akin to a liquid. indeed gas giants is a bit of a misnomer, as due to the pressures and densities deep within, the atmosphere would be in liquid state.

Answer 4

there is something like a hot liquid metallic hydrogen layer where you would be able to walk if you could bear the enormous pressure.