TODAY’S TV BEST BETS
‘Battle of the Nutcrackers’ Ovation, 5 a.m. Tchaikovsky-fest: A different staging of the ballet airs every weekday morning.
‘National Geographic Explorer: Space Race’
National Geographic, 5 p.m.
Since NASA’s robotic lander InSight touched down on Mars Nov. 26, we’ve been wondering: When will we have the technology for humans to stay healthy on the nine-month journey to the Red Planet? This space-themed episode spotlights one area of investigation — lemurs (!) — and whether we can learn to hibernate like the furry cuties.
‘CMA Country Christmas’ ABC, 7 p.m.
The ninth annual holiday music special returns with Reba McEntire hosting for a second year and also performing. Joining McEntire are Tony Bennett, Brett Eldredge, Amy Grant, Diana Krall, Martina McBride, Old Dominion, Brad Paisley, Lindsey Stirling and Brett Young, taking the stage for a night filled with Christmas classics and festive collaborations. ‘The Voice: Live Semifinal, Top 8 Performances’ NBC, 7 p.m.
The top eight artists perform live in front of coaches Kelly Clarkson, Jennifer Hudson, Adam Levine and Blake Shelton for America’s vote. Plus, the artists team up for competitive mashup duets.
‘Happy Together: Home Insecurity’
CBS, 7:30 p.m.
When one of Cooper’s (Felix Mallard) stalkers sneaks into Jake (Damon Wayans Jr.) and Claire’s (Amber Stevens West) house, they reluctantly decide to install a home security system in this new episode.
‘Magnum P.I.: Bad Day to Be a Hero’
CBS, 8 p.m. (guest star alert)
Corbin Bernsen guest-stars as a character known only as Icepick in this new episode, in which Magnum ( Jay Hernandez) must help Toni (guest star Jamie-Lynn Sigler) when her illegal poker game is robbed by masked gunmen.
‘DC’s Legends of Tomorrow: Legends of To-Meow-Meow’ The CW, 8 p.m.
After Constantine (Matt Ryan) breaks the cardinal Legend rule — you can’t change the past —he, Charlie (Maisie Richardson-Sellers) and Zari (Tala Ashe) try to deal with the ramifications without telling the rest of the Legends. Even though Zari encourages them to just fix the problem, Constantine and Charlie are determined to find another way.
‘No Sleep ’Til Christmas’
Freeform, 8 p.m. (original film)
This whimsical holiday romcom revolves around two insomniac strangers: Lizzie (Odette Annable), who lies awake planning her wedding, and Billy (Dave Annable), a low-key and sleep-deprived bartender. When they discover that they can only fall asleep while next to each other, what seems like an odd coincidence — and frankly a disruption to their lives — might be more meaningful than they’d like to admit.
‘MARS: Power Play’
National Geographic, 8 p.m.
Lukrum strikes a deal with Russia for exclusive mining rights. Uneasiness spreads over Olympus Town as Lt. Commander Mike Glenn (Gunnar Cauthery) undermines Hana ( Jihae) and endangers the members of Lukrum Colony as a result. And, a new baby — the first born on Mars — arrives two months early! In the Arctic Circle in the present day, nations attempt to work together to rein in corporate interests, protect fragile ecosystems and preserve indigenous lifestyles while fossil-fuel companies prioritize their own profit over the public good.
‘The Great Christmas Light Fight: All Stars’
ABC, 9 p.m.
As part of “25 Days of Christmas,” this special all-stars episode features the most magnificent and over-the-top displays in America.
‘Sacred’
PBS, 9 p.m.
Become immersed in the daily use of faith and spiritual practice in more than 25 countries. At a time when religious hatreds dominate headlines, explore faith as a primary human experience, and how people turn to ritual and prayer to navigate life.
‘Nightflyers: Transmission’ Syfy, 9 p.m.
D’Branin (Eoin Macken) has a breakthrough, Rowan (Angus Sampson) prepares for big changes and Lommie (Maya Eshet) seeks comfort in her past.
‘Who Do You Think You Are?: Josh Duhamel’ TLC, 9 p.m.
Duhamel travels to England to investigate the extraordinary life of his 12-times-great-grandfather and uncovers an astonishing, dark twist of interrogation and torture that rocks his belief system to the core.
‘Real Country: Heartbreak and Revenge’
USA Network, 10 p.m. Special guest Sara Evans joins the show tonight.