The “Doctor Who” franchise has been in the news a lot the last few days. John Barrowman, star of the spinoff series “Torchwood,” was in a car crash over the weekend during filming for the U.K. program “Fifth Gear.” Fortunately, Barrowman escaped with relatively minor injuries — cuts and bruises and some glass in his eye, which paramedics were able to remove. This morning (skip to the next paragraph if you don’t want to hear about the future of “Doctor Who”) the BBC revealed the costume for the next Doctor, Matt Smith. The Daily Mail has some more shots of the jacket/trousers/bow tie/boots ensemble. Filming for Smith’s run as the 11th Doctor began this week.

But if you live in the United States and don’t rely on grey-market torrents to get your fix of U.K. TV shows, the much bigger news is that “Torchwood: Children of Earth” starts its run on BBC America tonight. If you’re thinking about sitting down to watch it, here’s what you need to know.