How about, the solar system passes into a galactic arm carrying FAR more interstellar hydrogen than we thought was possible, cold dark matter (grate book title), and jupiter, saturn, all the gas giants, including the sun, get a fresh 'drink' of hydrogen. everything gets larger, all the 'other' gas giants turn into brown dwarves, while Jupiter becomes our Second Sun (better title), which starts a radical co-orbit situation with well, now binary, stars. Then it can get really wierd, like earth gets flung out into space or somehow ends up in the habitable range of this new binary pair... well, not with all those brown dwarves...
Hey, BA, I think THIS is neater than the REAL universe; WOO-WOO bound am I!!!

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Feynman
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Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.

Religion is a culture of faith; science is a culture of doubt.