That's the impression I got, especially from the movie.
From a scientific perspective it's really unlikely as there would be drastic climate differences between the planets, but also from a scientific perspective how would they be travelling between different solar systems without startrekky warp capabilities?
Interesting question. Maybe it is not about planets but about the moons of a single planet in the right distance from the sun? Terraformed moons, of course...
shareNice, that would make the most sense given the seemingly short travel times too.
Never even hinted at being the case of course, but fun to consider.
It looks something like this; https://www.reddit.com/r/firefly/comments/1h41j1/complete_map_of_the_verse/
But it's just a TV show, try to relax and just enjoy the ride.