Brian Koberlein, on Medium:
The simple division of our solar system into rocky and gassy worlds is the result of a complex planetary dance that in many ways defies the odds, and lies on the outskirts of what’s “normal” or, at least, average. But the galaxy is a very large place, with somewhere around 300 billion stars, and therefore, 300 billion chances at life, and of having rocky, Earth-like planets in their habitable zones. While there are likely many other planetary systems similar to ours, the vast majority will be devoid of anything like our home world. As we seek out new worlds with life — and potentially, new civilizations — on them, our best chance for an Earth-like planet might not be a planet like ours, but rather on a world that’s right out of Star Trek: the twin moons Remus and Romulus, orbiting a gas giant which in turn orbits its parent star.
For a long time I’ve loved the idea of a habitable moon orbiting a “hot jovian.” But it’s interesting that the particular configuration of our solar system (with its cold jovians) may not be all that common. Fortunately, as far as getting life started, I believe there’s more than one way to get the job done.