Hmm, I wonder if there are lots of variables that go into "likelihood of being hit by asteroid" - e.g. the size of the central star in the first place, and the

Hmm, I wonder if there are lots of variables that go into "likelihood of being hit by asteroid" - e.g. the size of the central star in the first place, and the resulting radius of the hab zone. It's also of not: if earth hadn't been hit by at least some asteroids, it mightn't have any water.