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Planetary RadioJanuary 31, 2017

The Final Countdown at Saturn

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On This Episode
Linda Spilker head shot
Linda Spilker

Cassini Project Scientist, Jet Propulsion Laboratory

Planetary Radio’s most frequent guest, Project Scientist Linda Spilker, returns with another update on the Cassini mission that is approaching its grand finale. Senior editor Emily Lakdawalla has a special announcement. Humans on Mars by 2033? Bill Nye sees a glimmer of hope. Our solar system’s biggest volcano is on the Red Planet. How big? Bruce and Mat share some dimensions on What’s Up.

Daphnis in the Keeler Gap

NASA / JPL-Caltech / SSI / Ian Regan

Daphnis in the Keeler Gap
Cassini was able to capture its closest-ever view of Daphnis toward the end of its mission, during its F-ring orbit phase, when it passed between the F and G rings once per orbit. Daphnis is only about 8 kilometers across.

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Trivia Contest

This week's prizes are a lovely Planetary Radio t-shirt, now available in both men’s and women’s styles. Also, a 200-point astronomy account, and a Planetary Society rubber asteroid.

This week's question:

Who sculpted the Fallen Astronaut statue left on the moon by the Apollo 15 astronaut Dave Scott?

To submit your answer:

Complete the contest entry form at or write to us at no later than Tuesday, February 7th at 8am Pacific Time. Be sure to include your name and mailing address.

Last week's question:

What solar system moon is closest in size to Mercury?


The answer will be revealed next week.

Question from the week before:

Approximately how wide is the combined, complex caldera of Olympus Mons, the Martian volcano?


The complex caldera at the summit of Mars volcano Olympus Mons measures about 60 by 80 kilometers, and is 3 kilometers deep.

Listen more: Humans to Mars, Cassini, events and announcements, Planetary Radio, Mars, Saturn's moons, Saturn, Bill Nye, Saturn's rings

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