In The Event One Wants a Gas Titan in His Worldbuilding Story

In recent years, we have discovered exoplanets that defy our traditional perspectives on how planets work. WASP-17b is twice as wide as Jupiter, yet half as massive, probably because of its orbital proximity to its sun.

Saturn itself is very confusing. It is second to Jupiter in diameter and mass. Despite that, Saturn is the lightest planet in the solar system, at only 0.687 grams per cubic centimeter. Its atmosphere is 75% hydrogen and 25% helium--could this have played a part in determining Saturn's record density?

So in the event that some worldbuilder creates a five-billion-year-old alternate Jupiter that is 11x greater in mass (much like HD 106906 b) yet lighter in density and still in orbit 483.8 million miles from the sun, would the overall structure be realistically sound? Would a super-Jupiter with an atmosphere 75% hydrogen and 25% helium help reduce its density to below regular-Jupiter?

posted almost 8 years ago

JohnWDailey‭

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