The truth about Charlie

Before he was primarily known for angry tweets and dating adult-film stars, Charlie Sheen made some decent films. A daylong marathon of his features on Encore offers mostly clunkers, but check out “Platoon” (7 p.m.) and “Wall Street” (9 p.m.) to see what real “winning” is all about. Saturday

A big bang

“Saturday Night Live” returns after an Olympics break with a gold-caliber host in Emmy winner Jim Parsons, who gets a chance to show that he can do more than just socially awkward geniuses (as if there are any other kind). Beck performs something you’ll never hear on the radio. 10:30 p.m. Saturday, KARE, Ch. 11

Are we alone?

A week of programming dedicated to our never-ending search for aliens kicks off with a new episode of “NASA’s Unexplained Files,” which reveals, for the first time, that E.T. is alive and, well, running a gas station in Montgomery, and that the moon is indeed made of cheese. 9 p.m. Sunday, Science

Neal Justin