Should a planet the size of Jupiter....?

Question

Should a planet the size of Jupiter have the same water and land proportioned such as the earth’s, be enveloped by an atmosphere similar to that of the earth, receive adequate sunlight akin to what the earth receives for its size, what would be the interesting repercussions/effects?

Answer 1

Due to gravitational compression Jupiter could never have an atmosphere like Earth's, the pressure is so great that hydrogen becomes a metalic liquid. Even more so because Earth is the densest planet in the Solar System, so at Earth's density Jupiter would be about twice as massive. Putting Jupiter's gravitational acceleration at just over 50 meters per second. Surface pressure would be 800 kPa compared to Earth's 101... It would still spin very fast because unlike the Earth the moons while huge, are miniscule compared to the planet; so it would still have its killer magnetic field and violent storms all over the surface.

Answer 2

Hello Jomar:

Hmm-m, a planet the size of Jupiter. Jupiter is 88,846 Miles in diameter. Earth is 7,926 Miles in diameter. So this mythical planet would be ten times wider than Earth, and having similar composition might have a mass 100 to 1000 times that of Earth. So it would have a huge gravitational pull.

You said nothing about this mythical planet's speed of rotation. That is a problem for us in suggesting possibilities for this projected planet situation. "Jupiter" is a gas giant, comprized mainly of hydrogen gas with some helium, and it has has no solid crust like the Earth. Jupiter is spinning so fast that material within the planet is thrown owtward making the planet appear to bulge at its center or equator. Were a solid, water covered, planet the size of Jupiter to spin at the same rate as Jupiter, I do not think that it would retain water within its seas and oceans. I think that large bodies of water would be in constant motion across the surface. I am not certain if such a mass could stick together in the face of such rapid spinning. Spinning slower would help a lot to preserve the entity as a whole.

With this much mass, the core of the planet would be extremely hot. Volcanic activity would be a dominant factor in the planet's existance. Plate shifting on the surface crust would be significantly faster than that on Earth. Having greater mass and gravity than the Earth, it is logical that the atmosphere would be thicker and more dense (heavier). So, the atmospheric pressure on this planet would be way in excess of 14 PSI. Retention of gas molecules would be excellent.

Somewhere along in here I have run out of ideas.