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A planet many times as massive as Jupiter was racing around its parent star in an incredibly close orbit, even closer than our planet Mercury's orbit of the sun. The intense energy from the star would have heated the atmosphere of the planet to well over 1,000 degrees, easily hot enough to cause gases to boil off the planet into space. What was a giant planet doing so close to a star, and how could it possibly manage to survive there?

I wonder if both scenarios might be right -- what if the inner planets start out as giant balls of gas just like the outer planets, but during the early stages of the newly formed solar system the Sun causes the gas to boil off of the closer planets over a hundred million years or so, eventually leaving just the denser, rocky residue that had originally been a small percentage of the young gas giant, but now remains as what we would recognize as an Earthlike (or Marslike/Venuslike) planet?