After 72 years and hundreds of books on the subject, you’d think we’d know everything about the 1941 attack on Pearl Harbor. But “Nova” (7 p.m., PBS, check local listings) uses forensics to disinter another fragment of evidence about the infamous December morning.

The attack on Pearl Harbor has long been seen as an aerial effort, a triumph of carrier-based planes over fixed installations. But Japanese mini-submarines also contributed to the destruction, and “Nova” reveals evidence of a fifth and hitherto unaccounted-for sub.

In addition to examining the metal evidence raised from its watery grave after seven decades, the researchers comb Japanese naval records and examine the hulls of still submerged vessels to determine whether torpedoes struck them from below as well as bombs from above. Combining science and history, this “Nova” serves up some serious detective work about one of the century’s most well-researched events.

• Fans of the late Steve Irwin should enjoy “Wild Recon” (8 p.m., Animal Planet), a new series featuring a loud, enthusiastic and seemingly fearless naturalist who throws himself into his work.

South African-born Donald Schultz parachutes into jungles to extract venom from dangerous snakes and wrestle with giant reptiles and other dangerous critters. He’s not just doing this to show off. Often, he’s the only guy who can get rare blood or DNA samples from endangered species. “Recon” puts an emphasis on science, but that doesn’t mean that Schultz’s stunts are any less death-defying.

• “The Biggest Loser” (7 p.m., NBC) is back, and it’s literally bigger than ever. This season features 11 family teams and the heaviest contestant ever, a Chicago man (participating with his mother) who tips the scales at 526 pounds. A set of twins has a combined weight that approaches 1,000 pounds.

Tonight’s other highlights

• Georgia Tech and Iowa meet in the Orange Bowl (7 p.m., Fox).

• On two episodes of “Scrubs” (ABC), students ponder the big picture (7 p.m.), family matters (8 p.m.).

• On two episodes of “Better Off Ted” (ABC), worked to death (7:30 p.m.), lost in translation (8:30 p.m.).

• Sam worries that he may have hidden terrorist connections on “NCIS: Los Angeles” (8 p.m., CBS).

• On part two of “The Emotional Life” (8 p.m., PBS, check local listings): facing anxiety and fear.

• A divorce case offers insight into Peter’s disgrace on “The Good Wife” (9 p.m., CBS).

• A new case features multiple victims with missing identities on “The Forgotten” (9 p.m., ABC).