“Alaska: Most Extreme” (Discovery 7 p.m.) Discovery Channel continues its Alaska Week promotion with this travel special documenting the Last Frontier’s extremes—from weather to altitude.
“Untamed Alaska” (Discovery 7 p.m.) Not only is Alaska extreme, mind you, it’s also untamed.
“Prison Break” (KASA-2 8 p.m.) Believe it or not, FOX’s seemingly limited concept action series enters its fourth season tonight. Apparently these guys are quite adept at breaking out of prison but really lousy about not getting caught and being sent back to prison—at which point they have to break out again, fulfilling the titular promise for yet another season.
Grey Gardens (HBO 6 p.m.) Drew Barrymore and Jessica Lange play two eccentric, estranged relatives of Jackie Kennedy Onassis in this dramatic adaptation of the cult documentary by Albert and David Maysles.
“World’s Strictest Parents” (CMT 7 p.m.) Soon to be followed by “World’s Most Negligent Parents” and, eventually, “World’s Most Abusive Parents.”
The Natalee Holloway Story (Lifetime Movie Network 6 p.m.) Despite the fact that—four years later—there are still few clues as to what happened to missing Alabama teen Natalee Holloway, Lifetime has managed to crank out a TV movie.
Knights of Bloodsteel (Sci-Fi 7 p.m.) This Canadian-made miniseries starring David James Elliott (“JAG”) and Christopher Lloyd (Back to the Future) features dragons, sorcerers and a title only fantasy nerds could love.
“Sit Down, Shut Up” (KASA-2 7:30 p.m.) From the creator of “Arrested Development” comes this animated sitcom about burned-out high school teachers. Among the impressive voice cast are Will Arnett, Jason Bateman, Kristin Chenoweth, Tom Kenny, Cheri Oteri and Henry Winkler.
The Courageous Heart of Irena Sendler (KRQE-13 8 p.m.) Anna Paquin stars in this TV biopic about a Polish social worker who saved hundreds of children during World War II.
“In Plain Sight” (USA 8 p.m.) The second season of this shot-in-Albuquerque series starts tonight.
“Jon & Kate Plus 8 Go Green!” (TLC 8 p.m.) Unless it’s from ptomaine poisoning, I’m not really interested.
“Eco Trip: The Real Cost of Living” (Sundance 7 p.m.) Wanna feel guilty about the way in which you live? Sundance Channel is here to help with its new documentary series exposing the environmental, economic and health impact of assorted everyday products. In tonight’s premiere, they’re ruining chocolate for you.
“The Phone” (MTV 11 p.m.) Justin Timberlake produces this reality/game show in which people who answer a random cell phone hidden somewhere in the city are asked to participate in a fast-paced, run-around-and-do-crap competition.
The First Millimeter: Healing the Earth (KNME-5 8 p.m.) It’s Earth Day, people. The least you could do is watch this documentary exploring solutions to global warming.