I had been thinking about what it is that makes some science fiction television shows successful, while others – despite how critically acclaimed they may be – only last for a season or two.

I decided that one differentiator was that some of them, like the original Star Trek, Farscape, and Battlestar Galactica, are ultimately about people exploring the unknown. Which is why so many of these shows are like westerns.

I write about this – and much more, including Stargate’s super-successful spinoff Stargate Atlantis – in the latest Channel Changer, which published today.