Sam discovers more about his past when he finds himself on his father’s trail on “Life on Mars” (9 p.m., ABC). “Mars” stars Jason O’Mara as Sam, a police detective who suffers a severe trauma only to awaken in 1973 working in a precinct house dominated by a cranky chief (Harvey Keitel) with a decidedly antique take on police procedure, not to mention retro attitudes toward women and minorities.

In each episode, “Mars” works through a self-contained crime story and presents new clues as to Sam’s strange and mystical predicament.

In a year hardly known for breakout hits, “Mars” has had to compete with the departing “ER” and the popular new CBS detective series “Eleventh Hour.”

This season has been hard on dramas with elaborate set-ups. The demise of NBC’s “My Own Worst Enemy” is a clear sign that convoluted mysteries have lost their allure. The rise of “NCIS,” the success of “The Mentalist” and the enduring dominance of the “CSI” franchise demonstrate viewers’ desire for an hour-long viewing experience with a beginning, middle and end.

Perhaps the gloom and uncertainty of the economy have given murky mysteries a bad name. And after a heated election that dominated the national conversation for more than a year, viewers may be looking for stories with resolutions that don’t require a major commitment.

Straddling the line between complex drama and straight-forward detective story, “Mars” may or may not survive this trend. If not, we may never know why Sam ended up in the year “Dark Side of the Moon” debuted and if he ever escapes.

Or, for that matter, if he cheats on his 2008 girlfriend (Lisa Bonet) with a fetching fellow officer (Gretchen Mol) from the Nixon era. As a song of that period extolled, if you can’t be with the one you love, love the one you’re with.

• Speaking of Mars, “Martian Chronicles” author Ray Bradbury appears with host Robert Osborne to act as guest-programmer for a night on Turner Classic Movies. His choices include two silent classics starring Lon Chaney, “The Phantom of the Opera” (7 p.m.) and “The Hunchback of Notre Dame” (8:45 p.m.). He also chose “Rebecca” (10:45 p.m.) and “Citizen Kane” (1 a.m.).

• Expedition week continues with “Lost Cities of the Amazon” (8 p.m., National Geographic). Peter Coyote narrates this documentary look at efforts to find legendary cities of gold described by a Spanish cleric accompanying early Spanish Conquistadors. Long consigned to the realm of myth and colonial propaganda, these stories have recently been supported by surprising archeological discoveries.

Tonight’s other highlights

• As tornadoes strike Camden, Randy assumes superpowers on “My Name is Earl” (7 p.m., NBC).

• Boston hosts Detroit in NBA action (7 p.m., TNT).

• Betty competes with Marc for a spot in a training course that could provide an elevation in salary and status on “Ugly Betty” (7 p.m., ABC).

• Accusations fly when nobody assumes responsibility for a mess in the microwave oven on “The Office” (8 p.m., NBC).

• Jack’s old friend (Steve Martin) admires Liz on “30 Rock” (8:30 p.m., NBC).