SERIESA Traveler's Guide to the Planets:
The landscape of Mars includes giant volcanoes and awe-inspiring canyons, and the low gravity means visitors would have superhuman jumping abilities -- but suffocate without a breathable atmosphere (6 and 9 p.m. National Geographic). The tour continues with visits to the inner planets, Venus and Mercury, at 7 and 10.
The Bachelor: On the Wings of Love: The final three bachelorettes join Jake on the island of St. Lucia, where each woman must decide if she wants to join Jake in the fantasy suite after a romantic date (8 p.m. ABC).
Life Unexpected: Lux tries to impress the high-school quarterback by offering to throw a party in Baze's loft in this new episode (9 p.m. KTLA).
24: President Taylor (Emmy winner Cherry Jones) pressures CTU for progress, but Jack's (Kiefer Sutherland) plan sends operatives into a panic, in this new episode (9 p.m. Fox).
Castle: When an assistant district attorney is murdered, Castle and Beckett's (Nathan Fillion, Stana Katic) investigation reveals that the victim, who was known for being tough on criminals, was involved in an illegal operation of his own, in this repeat (10 p.m. ABC).
Kell on Earth: As fashion week comes to a close, the staff has an event for Nicolas Petrou (10 p.m. Bravo).
Keeping Up With the Kardashians: Kourtney ends her relationship with Scott after he gets violently drunk in Las Vegas on Kim's birthday (10 p.m. E!).
SPECIALSFor Members Only:
Host Tom Reed reflects on the achievements of his extended family and recalls his first interview with author Alex Haley ("Roots").(Noon KSCI).
Westminster Kennel Club Dog Show: Opening night at the 134th edition of the annual show, from Madison Square Garden in New York. (6 p.m. CNBC).
SPORTSXXI Winter Olympics:
Women's hockey: Canada vs. Switzerland. (2:30 p.m. MSNBC).
College basketball: Kansas at Texas A&M (6 p.m. ESPN).