24: Live Another Day: Jack Is Back Saturday, 8:30 p.m., Fox
One way to fill time on a Saturday night is to devote a half-hour to the return of once and, presumably, future hero Jack Bauer. After a four-year layoff in which he tried other things — including the supernatural drama “Touch” — Kiefer Sutherland (pictured) is back for another very bad day when the series returns on Monday. (This time out, there will be only 12 episodes, but the season will still span the titular 24 hours.) If you fell out of touch with the gravelly-voiced, world-weary Bauer, here’s your chance to catch up and get a sneak peek at where in the world he is. (Hint: Big Ben is watching.)
The Real History of Science Fiction Saturday, 10 p.m., BBC America
This series tries to cover a lot of territory, from TV series to films to books to actual science. Tonight’s installment looks at the depiction and dramatic subtext of alien invasions, with thoughts from everyone from Richard Dreyfuss (pictured) to Neil Gaiman.
Saturday Night Live Saturday, 11:30 p.m., NBC
Our spidey senses tell us that Andrew Garfield is hosting and Coldplay is hoping to spin a web of tunefulness.
The Simpsons Sunday, 8 p.m., Fox
Springfield goes LEGO.
Resurrection Sunday, 9 p.m., ABC