* Parenthood (10/9c NBC)
After a delay to mid-season and some casting swaps, the family drama based on Ron Howard's hit 1989 film finally premieres. In the opener, Lauren Graham's character, Sarah Braverman, decides to move back home with her parents, played by Craig T. Nelson and Bonnie Bedelia. The move thrusts single mom Sarah and her two kids into the midst of a big, colorful extended family. The well-rounded cast also includes Peter Krause, Monica Potter, Dax Shepard and Erika Christensen.
* American Idol (8/7c Fox)
The Top 24 boldly strolled to center stage last week in the first live shows of Season 9, resulting in a sonic wave of uneven performances. While the female contingent showed promise and strength - inspiring Simon and Randy to predict that a female will win the Idol crown this season - too many of the men went flat and fell flat. But the attention shifts solely to the ladies tonight (minus the eliminated Janell Wheeler and Ashley Rodriguez), as the semifinal round continues with the 10 remaining female contestants performing.
* Lost (9/8c ABC)
Gee, there's a lighthouse, too? So many loose ends. Messrs. Cuse and Lindelof do have 12 episodes left (including this one) to tie them up but, as Sayid heatedly puts it to Dogen: "I want some answers!" Of course, Sayid says most things heatedly, or at least intensely, and he certainly does have issues with Dogen. At least Sayid also gets a tender Nadia interlude (and let's hope there's not yet another replay of her hit-and-run demise). Meanwhile, back at the temple, this season's batch of Others will have to deal with Claire.
* Nova (8/7c PBS)
Since astrophysicist Neil deGrasse Tyson first led the push to strip Pluto of its planetary status in 1999, a quest that rocketed to reality in 2006, he's been in the crosshairs of angry elementary students, space fanatics and noted Pluto booster Stephen Colbert. In this episode, he sets out to learn just why the tiny (by intergalactic standards) hulk of rock has attracted such a fanatical following. And, yes, the doc features Colbert, as well as Jon Stewart, Diane Sawyer and Brian Williams.
The second season starts on its new network soon after the cliff-hanger ending that left Russell bullet-ridden. Lydia is in denial about Russell and reluctant to move on, but she's assigned to work with Rene Cordero (Amaury Nolasco), a flashy detective with a hunger for the limelight. Chickie, who has lost the respect of her comrades after snitching about Dewey's drinking problem, is saddled with the department slacker. Meanwhile, Ben, almost finished with his training, waits for the Captain to sign his book.