1) “Snowfall” season-opener, 10 p.m. to midnight, FX; also, midnight and 2 a.m. When this show started, Franklin and Melody (shown here) were college-bound kids, smart and diligent. When the third season ended, he was big in the drug boom of 1980s Los Angeles; she was an addict who shot him. Then viewers had to wait; 17 months later, we finally get more. She vanished; he barely survived and is trying to end the chaos. This is beautifully written and filmed, but way too harsh for many viewers.
2) “Resident Alien,” 10 p.m., Syfy. It seemed simple at first: This outer-space alien would kill Harry, a lonely guy in a cabin, and assume his form. Alas, Harry was a doctor; now the fake-Harry must quickly learn medicine. He should have also learned more about Harry … whose wife has just arrived. Then there’s the little boy who is the only one who can see the alien’s true face. That leads to a terrific hour that manages to juggle drama with wonderful dabs of sly humor.
3) “Nova” and “Europe’s New Wild,” 9 and 10 p.m., PBS. Here are opposite worlds: The second hour has the Danube Delta, abundant with everything from tiny Mayflies to seven Asian water buffalo, imported to caress the landscape. The first hour views Mars; researchers use Death Valley for comparison. This will insert brief footage of last week’s Mars landing; mostly, it’s a fascinating view of the work that led up to it … and the incredible hurdles in the next decade, to bring samples home.
4) “Nancy Drew,” 9 p.m., CW. Here’s one helpful lessons: Always pay attention to a talking doll. And another: If a corpse shows up in your kitchen, promptly contact authorities; autopsies should be left to professionals. Nancy ignores both, in a fairly good hour that closes with two boosts for future plots.
5) “Name That Tune,” 8 and 9 p.m., Fox. “The Masked Dancer” has ended now – Gabrielle Douglas won, with Maxsim Chmerkovsky and Mackenzie Ziegler next – and “The Masked Singer” starts its new season in two weeks. Meanwhile, we get double “Tune,” with Jane Krakowski hosting.