All times Eastern.

• 6PM, Discovery Channel – How It’s Made: Firefighter boots; garden tools; automated machines; gypsum boards.
• 6PM, National Geographic – Naked Science: Dino Meteor. Scientists examine the origin and demise of dinosaurs in Canada, a Hawaiian volcano and a lake in upstate New York.
• 6PM, Travel Channel – Natural Wonders: The Northern and Central Rockies: A showcase of the extraordinary geological, biological and historical marvels that are found in the majestic northern and central Rockies, a terrain that extends from the northern reaches of the Canadian Yukon to the states of Montana and Wyoming.
• 6PM, Discovery Health – Code Blue: Witching Hour. Cases on Friday the 13th include a man who has been shot in the chest; a 28-year-old who starts vomiting and screaming after being in a minor car accident; and a three-year-old who spilled hot soup on himself. Also: a doctor reveals he’s dying.
• 6PM, Discovery Times – FBI Files: Deadly Business. A decapitation murder leads Miami-Dade police and FBI agents to a notorious cult, where they persuade a member to betray the charismatic leader. They also link the cult with other suspected murders.

6:30PM and on after the jump!

• 6:30PM, Discovery Channel – How It’s Made: Grinding wheels; compost; window blinds; milk.
• 6:30, G4 – Ninja Warrior: Human physical ability is tested in each episode, as 100 competitors push their limits through a physically demanding four-stage course.
• 7PM, Food Network – Good Eats: Artichokes: The Choke Is on You. Cooking techniques for artichokes.
• 7PM, Speed – Chop Cut Rebuild: Season Premiere. Five new vehicles are rolled out for step-by-step restoration.
• 7PM, Travel Channel – Natural Wonders: The Southern Rockies: The Southern Rockies reveal both natural wonders and a rich history, from the life-and-death struggles the wildlife face every day to the brave Native American and European pioneers who sought to find fortunes of gold.
• 7PM, Discovery Health – Impact: Stories of Survival: Ejection Seat Accident. A woman is attacked by bees and is stung more than 500 times; an Air Force pilot passes out in midair, then wakes up and ejects seconds before crashing; a college student is shot in the heart.
• 8PM, ESPN – NFL Draft Preview: A look at top prospects and team needs for the April 28-29 event in New York City.
• 8PM, Science Channel – Supervolcanoes: Extraordinary volcanic eruptions are examined, including those at Yellowstone and Krakatoa.
• 8PM, History Channel – Modern Marvels: World’s Biggest Machines 5. The world’s largest engineering feats are explored. Included: NASA’s wind tunnel and flight simulator at the Ames Research Center in California; a continuous mining machine in Pennsylvania; the London Eye observation wheel in England.
• 8PM, PBS – Nova: First Flower. The history of the flower is explored. There exist between 220,000 and 400,000 different types, yet little is known about the flower’s origins.
• 9PM, National Geographic – Impossible Moves: Towns. Engineers attempt to build and move 30 floating mansions to their new home in the waters off the coast of Victoria, British Columbia, the site of a futuristic floating community.
• 9:30PM, Discovery HD – An Inside Look: Return of the Buffalo. A historical perspective of the American buffalo population includes how the Sioux relied on their meat, hides and bones, and how the protection program enacted by Congress in 1894 led to a resurgence of the species.
• 9:30PM, VH1 – Hysteria: The Def Leppard Story: A teleplay about the successes and setbacks of the popular British rock band.
• 10PM, A&E – Jacked! Grand Theft Auto Unit: Following the members of a police auto-theft division as they set out “bait cars” and then chase thieves after the vehicles have been stolen.
• 10PM, Comedy Central – South Park: New episode!
• 10PM, Showtime – Penn & Teller: Bullshit!: Exorcism. The guys examine something that has bedeviled them for some time…exorcism.
• 10PM, Spike – Ultimate Fighter: New episode!
• 10:30PM, Food Network – Charm City Cakes: Playing Games. Duff incorporates his welding and sculpture skills into the creation of a giant gumball-machine cake for a Bat Mitzvah. Also: a Scrabble board cake; a 3D slot-machine cake.
• 10:30PM, Showtime – This American Life: Growth Spurt. Three triumphant stories of people “who are willing themselves to the next stage in their lives,” including a stand-up comic whose boyfriend was killed on Sept. 11, 2001.
• 11PM, Comedy Central – Daily Show: Author Jeremy Scahill.
• 11PM, History Channel – Modern Marvels: Mountain Roads. Mountain roads are the subject. Included: the Donner Pass in the Sierra Nevada mountain range; Pikes Peak in Colorado; The Going-to-the-Sun Road in Montana’s Glacier National Park; the Eisenhower Memorial Tunnel in Colorado.
• 11:30PM, Comedy Central – Colbert Report: Former Arkansas governor Mike Huckabee.