As the Cassini probe at Saturn prepares for its "Grand Finale" dive into the planet's atmosphere on Sept. 15, Science Channel is airing a new episode of "The Planets" that looks back on what we've learned about the ringed planet during the probe's 13-year stay. The new episode airs tonight (Sept. 12) at 10 p.m. EDT/PDT, and is hosted by retired NASA astronaut Mike Massimino.

On Sept. 15, at 7:50 a.m. EDT, Science Channel will go live to broadcast the probe's final moments. And then, on Sept. 19 at 9 p.m. EDT/PDT, a new episode of "Space's Deepest Secrets" will delve into the history of the mission, look back on its greatest discoveries and analyze the probe's final views as it made the plunge. [Cassini's Saturn Crash 2017: How to Watch Its 'Grand Finale']

In a clip from tonight's episode, a narrator introduces the splendor of the ringed planet — "but secretive Saturn has been holding out on us," he says. Scientists allude to the many mysteries that remain regarding the planet, and the surprises its exploration has revealed — plus the variety of its many moons, which are "a planetary explorer's dream," according to one researcher. Those moons might hold the key to finding modern-day life away from Earth, the narrator adds.

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