Eli5: In our solar system, why are all of the gas giants past the meteor belt? Is it just a coincidence? Do other solar systems have similar organizations, with some rocky planets, a meteor belt, then gas giant planets, or is ours unique?

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In: Planetary Science

Answer 1

There is no reason a solar system needs to be structured the way ours is. For a long time the most common type of planets we’d discovered in other solar systems were large gas giants, bigger than Jupiter, near their stars. However, this is partially because those were the easiest to see with the first types of telescopes used to find them. Since then planets a bit smaller than Neptune have been the most common type discovered. [A study released last year](https://www.scientificamerican.com/article/we-live-in-the-rarest-type-of-planetary-system1/) categorized solar systems we’ve studied by the sizes of their planets and their order, and found ones like ours with the inner planets being smaller than the outer planets were actually the least common. As far as I know, we have not yet developed a way to see asteroid belts in other solar systems, but it is likely they are fairly common.