From Starts with a Bang:
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.
With uniqueness comes realizations.
Here for why this is not welcome news for many. (cosmology).