TONIGHT’S BEST BETS

Flatliners FX 8:00 a.m.

Elliot Page, James Norton and Nina Dobrev star in this thrilling drama. Five medical students trigger their own neardeath experiences in the name of science. Trying to study the afterlife, their actions get progressively more extreme and dangerous.

What on Earth? DISC 9:00 a.m.

Scientists explore some of the earth’s most fascinating phenomenons in eight back-toback rebroadcasts of this documentary series. Narrator Steven Kearney explores bizarre markings seen from space in oceans and deserts across the planet.

Tough as Nails (3) WFSB 9:00 p.m.

Phil Keoghan returns to host Season 3 of this rougharound-the-edges competition series. Contestants show off their mental and physical toughness during a series of challenges at job sites across the United States, each hoping to win big in the finale.

Contestant Cyril “Zeus” Ontai III from Season 2 of “Tough As Nails”