"NOVA scienceNOW" (8 p.m., PBS): The monthly magazine show is back with stories that probe a daring experiment with a killer flu bug and how space-age technology is helping to decipher crumbling,

"NOVA scienceNOW" (8 p.m., PBS): The monthly magazine show is back with stories that probe a daring experiment with a killer flu bug and how space-age technology is helping to decipher crumbling, ancient manuscripts. Also: Long before the dinosaurs, something triggered Earth's most profound mass extinction, and clues suggest it was not the result of an asteroid impact, like the one that extinguished the dinosaurs much later on. Does the culprit pose a threat to our future, and can scientists pin it down? And, in a story about robots with emotions, the program visits roboticist Cynthia Breazeal, whose projects include a touch-sensitive teddy bear called the Huggable, which may someday comfort patients and assist caregivers in hospital pediatric wards.
"Tony Bennett: An American Classic" (8 p.m., NBC): Forget the cake and all the candles. Just tune in for this one-hour special that will celebrate the 80th birthday of this legendary entertainer. The tribute, directed by Rob Marshall ("Chicago"), showcases Bennett performing some of his most memorable songs in duets with Barbra Streisand ("Smile"), Christina Aguilera ("Steppin' Out With My Baby"), Elton John ("Rags to Riches"), Stevie Wonder ("For Once In My Life"), k.d. lang ("Because of You") and more. The special takes viewers on a journey through the singer's life, with narration by such stars as John Travolta, Robert De Niro, Catherine Zeta-Jones, Bruce Willis and Billy Crystal.
"American Music Awards" (8 p.m., ABC): Kanye West is up for two "American Music Awards," so let's hope he doesn't throw a hissy fit if he fails to win. The list of performers for tonight's gala in Los Angeles includes Beyonce, the Dixie Chicks, Gwen Stefani, Josh Groban, Mary J. Blige, Nelly Furtado and Rascal Flatts. Funnyman Jimmy Kimmel is host.
"Frontline: Living Old" (9 p.m., PBS): More Americans are living longer these days. That sounds like a good thing, but "Living Old," the latest offering from Frontline, explains that there can be severe consequences to this longevity. They include serious chronic illnesses and protracted physical declines, along with strains on families and the health-care system. Do we have a major societal crisis in the making?