Friday Night Lights Friday Night Lights

Friday Night Lights
9 pm/ET NBC
The Lights are going down on the third season of NBC's critically acclaimed (and recently renewed!) drama. In tonight's season finale, everyone's eyes are on the future, some more enthusiastically than others. Billy and Mindy finally tie the knot, while Eric anxiously awaits the status of his contract review. Meanwhile, the teens are doing their own reflecting as Tyra waits for news about college, Matt considers leaving his grandma and Julie, and Riggins and Lyla wonder about the future of their relationship. —Brie Hearn

Terminator: The Sarah Connor Chronicles
8 pm/ET FOX
After two seasons of raising hell, someone finally scheduled Sarah Connor a little one-on-one time with a priest, to whom she confesses a predictably not-so-cheery view of the world. Elsewhere, Weaver angles for an appointment with the boy who's destined to save humanity from the machines, while John and Cameron have a heart-to-microchip chat in tonight's season finale. —Michael Chant

9 pm/ET ABC
Much has been made of the President and Mrs. Obama's recent meeting with Queen Elizabeth II, but what about Princess Maddison? Well, there isn't one, of course, but on another trip to the United Kingdom, Jo confronts a tantrum-throwing 9-year-old girl who's expecting her coronation any day now. To make matters worse, this wannabe royal treats her parents like lowly serfs, and she's grooming her 7-year-old brother to be the marquis of misbehavior. —Joe Friedrich

Ghost Whisperer
8 pm/ET CBS
Actress and singer Hilary Duff makes an appearance as a mysterious woman with whom a male ghost has some unfinished business. Melinda and Eli try to help the man, and it's revealed that the young woman may be connected to another man's death. —Bill Ecklund

400 Years of the Telescope
10 pm/ET PBS (check local listings)
Astrophysicist Neil deGrasse Tyson narrates this history of the telescope, which spans from Galileo's first look into the heavens in 1609 to present day, featuring extraordinary imagery captured by the modern-day Hubble Space Telescope. Astrophysicists reflect on momentous discoveries, discuss dark energy and preview what's next on the horizon: stadium-size telescopes and a radio-telescope array, which is intended to be used in an effort to glimpse the first moments following the Big Bang. —Jeff Gemmill