A decades-old lunar mystery gets an update in this week's Planetary Radio. Matt Siegler from the Planetary Science Institute shares his team's surprising findings about the granite formation that might lie beneath Compton-Belkovich, a thorium-rich hot spot on the far side of the Moon. Ambre Trujillo, Planetary Society Digital Community Manager, gives an update on the new member community app Space Trivia Contest, and Bruce Betts, chief scientist of The Planetary Society, shares What's Up in the night sky.


Discover more at: https://www.planetary.org/planetary-radio/2023-subsurface-granite-on-the-moon

A decades-old lunar mystery gets an update in this week's Planetary Radio. Matt Siegler from the Planetary Science Institute shares his team's surprising findings about the granite formation that might lie beneath Compton-Belkovich, a thorium-rich hot spot on the far side of the Moon. Ambre Trujillo, Planetary Society Digital Community Manager, gives an update on the new member community app Space Trivia Contest, and Bruce Betts, chief scientist of The Planetary Society, shares What's Up in the night sky.
 Discover more at: <a href="https://www.planetary.org/planetary-radio/2023-subsurface">https://www.planetary.org/planetary-radio/2023-subsurface-granite-on-the-moon</a>

Planetary Radio brings you the human adventure across our Solar System and beyond. We visit each week with the scientists, engineers, leaders, advocates, and astronauts who are taking us across the final frontier. Regular features raise your space IQ while they put a smile on your face. Join host Sarah Al-Ahmed and Planetary Society colleagues including Bill Nye the Science Guy and Bruce Betts as they dive deep into space science and exploration. The monthly Space Policy Edition takes you inside the DC beltway where the future of the US space program hangs in the balance. Visit planetary.org/radio for an episode guide and much more.

Planetary Radio brings you the human adventure across our Solar System and beyond. We visit each week with the scientists, engineers, leaders, advocates, and astronauts who are taking us across the final frontier. Regular features raise your space IQ while they put a smile on your face. Join host Sarah Al-Ahmed and Planetary Society colleagues including Bill Nye the Science Guy and Bruce Betts as they dive deep into space science and exploration. The monthly Space Policy Edition takes you inside the DC beltway where the future of the US space program hangs in the balance. Visit planetary.org/radio for an episode guide and much more.

Planetary Radio: Space Exploration, Astronomy and Science

Planetary Radio brings you the human adventure across our solar system and beyond. We visit each week with the scientists, engineers, leaders, advocates, and astronauts taking us across the final frontier. Regular features raise your space IQ while they put a smile on your face. Join host Sarah Al-Ahmed and Planetary Society colleagues including Bill Nye, the Science Guy, and Bruce Betts, chief scientist for The Planetary Society, as they dive deep into the latest space news. The monthly Space Policy Edition takes you inside the DC beltway with Casey Dreier and Jack Kiraly to discuss the politics of space exploration in the US and advocacy actions you can take to support the missions that matter. Visit planetary.org/radio for the space trivia contest, an episode guide, and much more.

Planetary Radio brings you the human adventure across our solar system and beyond. We visit each week with the scientists, engineers, leaders, advocates, and astronauts taking us across the final frontier. Regular features raise your space IQ while they put a smile on your face. Join host Sarah Al-Ahmed and Planetary Society colleagues including Bill Nye, the Science Guy, and Bruce Betts, chief scientist for The Planetary Society, as they dive deep into the latest space news. The monthly Space Policy Edition takes you inside the DC beltway with Casey Dreier and Jack Kiraly to discuss the politics of space exploration in the US and advocacy actions you can take to support the missions that matter. Visit planetary.org/radio for the space trivia contest, an episode guide, and much more.

Matt Siegler from the Planetary Science Institute shares his team's surprising findings about the granite formation that might lie beneath Compton-Belkovich, a thorium-rich hot spot on the far side of the Moon.

Subsurface granite on the Moon? The anatomy of a lunar hot spot

Could a single ancient impact have briefly transformed one of the Solar System’s darkest moons into a cryovolcanic world?

When Voyager 2 flew past Uranus in 1986, it captured the only close-up images we have of Umbriel, a heavily cratered, charcoal-dark satellite long considered geologically inactive. But one feature stands out: a bright ring inside the 131-kilometer-wide Wunda crater.

In this episode, Sarah Al-Ahmed speaks with Adeene Denton, NASA postdoctoral program fellow at the Southwest Research Institute, about her team’s new study published in the Journal of Geophysical Research: Planets. Using shock physics simulations, Denton and her colleagues reconstruct the impact that formed Wunda crater to determine what Umbriel’s interior must have been like at the time. Their modeling explores whether impact-induced cryovolcanism can explain the bright deposits observed on the crater floor.

Then, in What’s Up, Bruce Betts, chief scientist of The Planetary Society, joins Sarah to break down one of the key mechanisms that keeps icy moons from freezing solid, tidal heating driven by orbital resonance. 

Discover more at: https://www.planetary.org/planetary-radio/2026-cryovolcanism-on-umbriel

Could a single ancient impact have briefly transformed one of the Solar System&rsquo;s darkest moons into a cryovolcanic world?
When Voyager 2 flew past Uranus in 1986, it captured the only close-up images we have of Umbriel, a heavily cratered, charcoal-dark satellite long considered geologically inactive. But one feature stands out: a bright ring inside the 131-kilometer-wide Wunda crater.
In this episode, Sarah Al-Ahmed speaks with Adeene Denton, NASA postdoctoral program fellow at the Southwest Research Institute, about her team&rsquo;s new study published in the Journal of Geophysical Research: Planets. Using shock physics simulations, Denton and her colleagues reconstruct the impact that formed Wunda crater to determine what Umbriel&rsquo;s interior must have been like at the time. Their modeling explores whether impact-induced cryovolcanism can explain the bright deposits observed on the crater floor.
Then, in What&rsquo;s Up, Bruce Betts, chief scientist of The Planetary Society, joins Sarah to break down one of the key mechanisms that keeps icy moons from freezing solid, tidal heating driven by orbital resonance.&nbsp;
Discover more at: <a href="https://www.planetary.org/planetary-radio/2026-cryovolcanism-on-umbriel">https://www.planetary.org/planetary-radio/2026-cryovolcanism-on-umbriel</a>

A new study explores whether a massive ancient impact briefly triggered cryovolcanism on Uranus’s moon Umbriel. Sarah Al-Ahmed speaks with Adeene Denton about how crater modeling reveals clues to the moon’s hidden interior.

Did an impact trigger cryovolcanism on Umbriel?

They informed and entertained together throughout the first 20 years of Planetary Radio. Listen in as the Society’s chief scientist and book club edition host Mat Kaplan share the mic once again for a delightful conversation about Dr. Betts’ two new space books for young people. “Are We Alone?” introduces the search for life across the Universe, while “The Size of Space” collects many of Bruce’s brilliant and hilarious ways to cut our Solar System down to human size.


Discover more at: https://www.planetary.org/planetary-radio/book-club-bruce-betts

They informed and entertained together throughout the first 20 years of Planetary Radio. Listen in as the Society&rsquo;s chief scientist and book club edition host Mat Kaplan share the mic once again for a delightful conversation about Dr. Betts&rsquo; two new space books for young people. &ldquo;Are We Alone?&rdquo; introduces the search for life across the Universe, while &ldquo;The Size of Space&rdquo; collects many of Bruce&rsquo;s brilliant and hilarious ways to cut our Solar System down to human size.
 Discover more at: <a href="https://www.planetary.org/planetary-radio/book-club-bruce-betts">https://www.planetary.org/planetary-radio/book-club-bruce-betts</a>

Bruce Betts helps us explore the latest and last in his excellent library of space books for young people. He and host Mat Kaplan take up “Are We Alone?” and “The Size of Space.”  

Book Club Edition: Planetary Society Chief Scientist Bruce Betts’ latest for kids

This week on Planetary Radio, we mark a major leadership transition at The Planetary Society. Host Sarah Al-Ahmed sits down with Bill Nye, outgoing chief executive officer and newly appointed chief ambassador of The Planetary Society, and Jennifer Vaughn, incoming chief executive officer and former chief operating officer, for a candid conversation about this long-planned transition. Together, Bill and Jenn reflect on how the organization, under their shared leadership, grew into the world’s largest and most effective nonprofit dedicated to advancing the scientific exploration of space.

Then, Bruce Betts, chief scientist of The Planetary Society, joins Sarah for What’s Up. They discuss an upcoming planetary alignment on and around February 28, 2026.

Discover more at: https://www.planetary.org/planetary-radio/2026-jennifer-vaughn-ceo

This week on Planetary Radio, we mark a major leadership transition at The Planetary Society. Host Sarah Al-Ahmed sits down with Bill Nye, outgoing chief executive officer and newly appointed chief ambassador of The Planetary Society, and Jennifer Vaughn, incoming chief executive officer and former chief operating officer, for a candid conversation about this long-planned transition. Together, Bill and Jenn reflect on how the organization, under their shared leadership, grew into the world&rsquo;s largest and most effective nonprofit dedicated to advancing the scientific exploration of space.
Then, Bruce Betts, chief scientist of The Planetary Society, joins Sarah for What&rsquo;s Up. They discuss an upcoming planetary alignment on and around February 28, 2026.
Discover more at: <a href="https://www.planetary.org/planetary-radio/2026-jennifer-vaughn-ceo">https://www.planetary.org/planetary-radio/2026-jennifer-vaughn-ceo</a>

A new chapter begins at The Planetary Society as Jennifer Vaughn becomes CEO and Bill Nye steps into his new role as chief ambassador. 

Subsurface granite on the Moon? The anatomy of a lunar hot spot

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