Tuesday on TV

NCIS (7 p.m., Ch. 2): Gibbs' former mother-in-law (guest star Gena Rowlands) witnesses a murder.

Nova (7 p.m., Ch. 7): Neil deGrasse Tyson investigates why so many people are so passionate about the planet Pluto. Or is it a planet?

American Idol (7 p.m., Ch. 13): The 10 remaining female contestants perform.

NCIS: Los Angeles (8 p.m., Ch. 2): A lieutenant dies under questionable circumstances.

Lost (8 p.m., Ch. 4): Sayid makes a tough decision.

Southland (8 and 11 p.m., TNT): The first of six new episodes of this excellent crime drama. It's the show NBC stupidly canceled and TNT picked up.

The Good Wife (9 p.m., Ch. 2): Diane and Alicia try to convince a woman to testify against her husband.

20/20 (9:02 p.m., Ch. 4): In one segment of a "Before They Were Famous" installment, George Clooney's father, Nick — the former anchorman at KSTU-Ch. 13 — gives a tour of the actor's childhood home.

Frontline (9 p.m., Ch. 7): "The Suicide Tourist" reports on a Swiss nonprofit group that helps terminally ill people end their lives.

Late Show (10:35 p.m., Ch. 2): Mitt Romney is David Letterman's guest. And Sarah Palin appears on The Tonight Show (10:35 p.m., Ch. 5) with Jay Leno.

White Collar (11 p.m., USA): The daughter of Neal's friend is kidnapped.