Planetary Radio: Space Exploration, Astronomy and Science

Only six people have received The Planetary Society’s Cosmos Award for Outstanding Public Presentation of Science. We were honored to present it to author and historian Dava Sobel in May of 2025. She has created a brilliant library of books that illuminate the lives and work of great scientists, many of whom have been under-appreciated. Each of Dava’s works is also overflowing with the wonder of science and discovery. It’s no wonder we decided to feature Dava and her books in the Society book club. That month-long celebration was capped by a live, online interview conducted by Dava’s friend and fan Mat Kaplan.  Here’s that conversation.  Discover more at: https://www.planetary.org/planetary-radio/book-club-dava-sobelSee omnystudio.com/listener for privacy information.

Pack your cosmic suitcase. This week on Planetary Radio, host Sarah Al-Ahmed is joined by Mark McCaughrean, astronomer, science communicator, and former Senior Advisor for Science & Exploration at the European Space Agency, to talk about his new book, “111 Places in Space That You Must Not Miss.” Part of the popular “111 Places” travel series, the book transforms the guidebook format into a tour across the Solar System and beyond, from Apollo landing sites on the Moon to Europa’s hidden oceans, and even the afterglow of the Big Bang. Mark shares highlights from the book, stories from his career on missions like Hubble, Rosetta, and the James Webb Space Telescope, and reflections on how science and imagination come together to inspire exploration. And in this week’s What’s Up, Planetary Society Chief Scientist Bruce Betts joins Sarah to talk about his brand-new children’s books, “The Size of Space” and “Are We Alone?,” part of our growing series with Lerner Publishing Group. Discover more at: https://www.planetary.org/planetary-radio/2025-111-places-in-spaceSee omnystudio.com/listener for privacy information.

This week on Planetary Radio, we look forward to International Observe the Moon Night on October 4, 2025. Host Sarah Al-Ahmed speaks with Staci Horvath, outreach coordinator for NASA’s Solar System Exploration Division at Goddard Space Flight Center and director of International Observe the Moon Night, and Theresa Summer, astronomy educator at the Astronomical Society of the Pacific, about the history of the event, how it connects people around the world, and the many ways you can participate. We also hear from Kate Howells, public education specialist at The Planetary Society, about her new book, “Moons: The Mysteries and Marvels of Our Solar System,” which combines striking space images and original illustrations to showcase the surprising diversity of moons in our Solar System. And Chief Scientist Bruce Betts joins Sarah for What’s Up with tips for observing the Moon and other wonders in the night sky. Discover more at: https://www.planetary.org/planetary-radio/2025-international-observe-the-moon-nightSee omnystudio.com/listener for privacy information.

NASA, the crown jewel of 20th-century technocratic liberalism, was the first to land humans on the Moon but now depends on SpaceX for its access to space. Atlantic writer Franklin Foer believes this reflects a diminishment of national capability and that NASA was inadvertently responsible for its own decline. He traces this transformation from a collective pursuit of higher values to a more individualistic — and idiosyncratic — motivation based on utility and extraction, and ties it to a larger trend in American politics over the past 50 years. Along the way, Frank and host Casey Dreier discuss if Elon Musk is the antithesis of Carl Sagan, the tensions between individualism and collectivism in American politics, and the role of the romantic ideal in the symbolism of space exploration. Discover more at: https://www.planetary.org/planetary-radio/franklin-foer-on-nasas-declineSee omnystudio.com/listener for privacy information.

For decades, Uranus has puzzled scientists. Unlike the other giant planets, Voyager 2’s 1986 flyby suggested the ice giant emitted no excess heat. Now, thanks to new analyses of Voyager data, decades of ground-based and space-based observations, and refined models, scientists have confirmed that Uranus does radiate more heat than it receives from the Sun. Host Sarah Al-Ahmed speaks with atmospheric scientist Michael Roman (Assistant Professor at the Universidad Adolfo Ibáñez in Chile) about his team’s new study showing Uranus emits around 12.5% more energy than it absorbs. Together, they explore what this means for our understanding of Uranus’s atmosphere, its bizarre seasonal cycles, the planet’s violent past, and why these findings strengthen the case for a future flagship mission to the Solar System’s overlooked ice giants.Stick around for What’s Up with Bruce Betts, Planetary Society chief scientist, for a look at Uranus’ newly discovered moon and a new random space fact. Discover more at: https://www.planetary.org/planetary-radio/2025-uranus-energy-balanceSee omnystudio.com/listener for privacy information.

BASILISK, the first esports organization dedicated to promoting science, has teamed up with The Planetary Society and Caltech’s Institute for Quantum Information and Matter to bring the banner of “Science Victory” to gamers around the world. Their roster includes world champions in StarCraft II, chess, Magic: The Gathering, and fighting games, all united by a shared mission to inspire the next generation of scientists. Joining us to talk about this unique collaboration is Kyle Hill, award-winning science communicator and BASILISK’s head of science education and outreach. Kyle shares how his career in science communication led him from YouTube into the world of professional gaming, where science and play are coming together in powerful new ways. Then, stick around for What’s Up with Bruce Betts, our chief scientist, as we share our favorite space-themed video games and a new random space fact. Discover more at: https://www.planetary.org/planetary-radio/2025-basiliskSee omnystudio.com/listener for privacy information.

In 2020, the YSES-1 system became the first directly imaged multiplanetary system around a Sun-like star. It features two giant exoplanets orbiting a star just 16 million years old. Now, the James Webb Space Telescope is revealing new insights into these distant worlds. Host Sarah Al-Ahmed speaks with Kielan Hoch, Giacconi Fellow at the Space Telescope Science Institute and principal investigator of the JWST program that captured these observations, and Emily Rickman, ESA science operations scientist at STScI and member of the JWST Telescope Scientist Team for coronagraphy. They explore what makes this system so unusual, including a dusty circumplanetary disk around YSES-1b and high-altitude silicate clouds in the atmosphere of YSES-1c. Later in the show, Bruce Betts joins for What’s Up to talk about how future telescopes like the Habitable Worlds Observatory could help us image smaller, colder, and older planets. Discover more at:  https://www.planetary.org/planetary-radio/2025-yses-1See omnystudio.com/listener for privacy information.

Author Frank White has interviewed well over 100 astronauts. Almost all of them report the sense of awe they experienced as they looked down or back at Earth, and how deeply this has affected their understanding and appreciation of our planet and the Cosmos. It’s what author Frank White calls The Overview Effect. Frank joined Planetary Society Senior Communications Adviser Mat Kaplan for a deep conversation about the ideas he shares in his book of the same name, now in its fourth edition. Here’s a great introduction to the Universe-spanning yet very personal ideas Frank has shared.   Discover more at: https://www.planetary.org/planetary-radio/book-club-frank-whiteSee omnystudio.com/listener for privacy information.

What do “Star Trek,” space advocacy, and the fight to save NASA science have in common? In this episode of Planetary Radio, we share a special panel recorded live at STLV: Trek to Vegas 2025, featuring Robert Picardo, actor and Planetary Society board member who played the Emergency Medical Hologram on ”Star Trek: Voyager,” and Tim Russ, actor, telescope enthusiast, and Voyager’s Lt. Tuvok. They’re joined by Andrew Pauly, director of marketing at The Planetary Society, and Ambre Trujillo, the Society’s digital community manager, for a conversation about how science fiction inspires real-world space exploration — and how fans can take action to protect it. Later in the episode, Jack Kiraly, director of government relations at The Planetary Society, discusses the recent wave of NASA employee departures and what it could mean for the future of space science. Then, in What’s Up, our Chief Scientist Bruce Betts reflects on the end of NASA’s Lunar Trailblazer mission. Discover more at: https://www.planetary.org/planetary-radio/2025-a-star-trek-futureSee omnystudio.com/listener for privacy information.

Just three interstellar objects have ever been detected in our Solar System, each arriving from the depths of interstellar space. In this episode, we explore the latest: 3I/ATLAS, a newly discovered interstellar comet first spotted on July 1, 2025. Bryce Bolin, research scientist at Eureka Scientific, joins host Sarah Al-Ahmed to share what makes this object special. As one of the few astronomers who has studied all three known interstellar objects—1I/ʻOumuamua, 2I/Borisov, and now 3I/ATLAS—he offers unique insight into how these rare visitors expand our understanding of planetary systems beyond our own. We also check in with Bruce Betts, chief scientist of The Planetary Society, for a look at the upcoming ESA and JAXA’s Comet Interceptor mission, which may one day chase down a future interstellar comet. Discover more at: https://www.planetary.org/planetary-radio/2025-3i-atlasSee omnystudio.com/listener for privacy information.

The 2020s will be a decisive decade for in-space nuclear power. So argues Dr. Bhavya Lal, whose new report reframes the conversation around a simple idea: power, not propulsion, is nuclear's most immediate and disruptive capability. Power is what enables humans to stay and build on distant locales; without an abundance of it, she warns, we will never be more than visitors. But in an era of super heavy-lift capability, does this vision still require a nuclear solution, or can we simply brute-force our future in space with cheaper alternatives? Discover more at: https://www.planetary.org/planetary-radio/bhavya-lal-space-nuclear-powerSee omnystudio.com/listener for privacy information.

How do astronauts get quality sleep in space? Erin Flynn-Evans, director of the Fatigue Countermeasures Laboratory at NASA Ames Research Center, joins Planetary Radio to explore how her team studies sleep, fatigue, and circadian rhythms to keep astronauts healthy and mission-ready. She shares how her team translates sleep science into actionable strategies for NASA crews, and how a chance job as a sleep technician led her on a path to spaceflight research. Later in the show, Casey Dreier, The Planetary Society’s chief of space policy, and Jack Kiraly, our director of government relations, provide a quick update on NASA’s budget and what it means for the agency’s future. Then, Bruce Betts, our chief scientist, joins us for What’s Up to explore how and why our robotic spacecraft sometimes need to power down and rest. Discover more at: https://www.planetary.org/planetary-radio/2025-sleep-in-spaceSee omnystudio.com/listener for privacy information.

On July 14, 2015, NASA’s New Horizons spacecraft made its historic flyby of Pluto, transforming our understanding of this distant world. Ten years later, we’re celebrating that iconic moment and the mission that made it possible. We begin with Alan Stern, principal investigator of the New Horizons mission, who reflects on the mission’s origins, its most surprising discoveries, and what comes next as New Horizons continues its journey through the Kuiper Belt. Then we check in with Adeene Denton, NASA postdoctoral program fellow at the Southwest Research Institute, who just returned from the “Progress in Understanding the Pluto System: 10 Years After Flyby” conference held at the Johns Hopkins University Applied Physics Laboratory. Adeene shares highlights from the event, which brought together scientists to explore new results from New Horizons, JWST, Hubble, and ground-based observatories on Pluto, Charon, and the broader Kuiper Belt. Finally, Planetary Society Director of Government Relations Jack Kiraly joins us with a major update on the ongoing fight to protect NASA science from devastating budget cuts. And don’t miss What’s Up with our Chief Scientist, Bruce Betts. We’re talking Arrokoth, the most distant Kuiper Belt object New Horizons visited after Pluto. Discover more at: https://www.planetary.org/planetary-radio/2025-new-horizons-pluto-flyby-10th-anniversarySee omnystudio.com/listener for privacy information.

Author Andy Weir was as shocked as anyone when The Martian became a top bestseller novel in the US. He repeated that achievement with his equally mind-blowing science fiction masterpiece Project Hail Mary. Former Planetary Radio host Mat Kaplan welcomed Andy in April of 2023 for the first livestreamed author conversation in The Planetary Society's member book club. Now, with the film version of Project Hail Mary approaching, we’re proud to begin making these insider interviews available to Planetary Radio listeners. We’ll post them on the third Friday of each month. Join us as we talk with Andy about his obsession with getting the science right while his reluctant and unlikely hero attempts to save humanity from a deep space scourge. Discover more at: https://www.planetary.org/planetary-radio/book-club-andy-weirSee omnystudio.com/listener for privacy information.

What happens when scientists, students, space communicators, and refugee engineers float together in zero gravity? Former Planetary Radio host Mat Kaplan joins a remarkable group of flyers aboard a Zero-G flight organized by Space for Humanity. You’ll hear from participants and mentors including Emily Calandrelli, Sian Proctor, and Roxy Williams, as well as Space for Humanity Executive Director Antonio Peronace and Zero-G CEO Kevin Sproge. Together, they share how a few moments of weightlessness offered a powerful shift in perspective. We explore the mission to make space more inclusive, the awe of the “overview effect,” and what it means to carry that inspiration back down to Earth. Then, Bruce Betts joins us for What’s Up. Discover more at: https://www.planetary.org/planetary-radio/2025-mat-kaplan-zero-gSee omnystudio.com/listener for privacy information.

The Vera C. Rubin Observatory has shared its first public images, revealing millions of galaxies, stars, and asteroids in stunning detail. Stephanie Deppe, astronomy content strategist at Rubin Observatory, joins us to explain what makes these images so revolutionary, how the observatory works, and what’s coming next as Rubin prepares for its ten-year Legacy Survey of Space and Time. Later in the show, we reflect on the life and legacy of the observatory’s namesake, Vera Rubin, the groundbreaking astronomer who provided the first convincing evidence of dark matter. Jess Soto, STEM Strategies Coordinator at Mount Wilson Observatory and creator of Science Women Shirts, reflects on Rubin’s efforts to open up opportunities for women in space science. Then we close out the show with Bruce Betts in our regular What’s Up segment, featuring the discovery of a brand-new interstellar object, 3I/ATLAS, the third known object to travel through our Solar System from interstellar space. Discover more at: https://www.planetary.org/planetary-radio/2025-first-images-rubin-observatorySee omnystudio.com/listener for privacy information.

Have Democrats ceded leadership in space policy? That’s what Mary Guenther believes. She’s the Director of Space Policy at the Progressive Policy Institute and the author of an editorial that claims Democrats have ceded their leadership. She traces the party’s arc from Obama-era reforms to recent data showing that Democrats introduced a third fewer space bills than Republicans in recent years, and proposes ways that the party should embrace this forward-looking field while tying it to their core issues of job creation, supply chains, and climate science.See omnystudio.com/listener for privacy information.

Recorded at the 2025 Humans to the Moon and Mars Summit (H2M2) in Washington, D.C., this episode features two powerful conversations about the future of human space exploration. Hosted by Mat Kaplan, senior communications adviser at The Planetary Society, these panel discussions explore the scientific and diplomatic foundations guiding humanity’s journey beyond Earth. The first panel, Space Science: A Vital National Interest, features James Green, former NASA chief scientist and chair of the Explore Mars advisory board, James Garvin, chief scientist at NASA Goddard Space Flight Center, Britney Schmidt, astrobiologist and associate professor at Cornell University, and John Mather, Nobel Prize–winning astrophysicist and senior scientist for the James Webb Space Telescope. They discuss how space science drives innovation, strengthens U.S. national priorities, and deepens our understanding of the universe, especially in the face of proposed funding cuts. In the second panel, Artemis Accords: International Collaboration in Deep Space, Mike Gold of Redwire, Marc Jochemich of the German Aerospace Center (DLR), Adnan Mohammad Alrais of the Mohammed bin Rashid Space Centre, and Sohair Salam Saber of The Hague Institute for Global Justice explore how diplomacy and shared values are shaping global participation in lunar exploration. The conversation also highlights the Washington Compact, an effort to bring shared values and responsible behavior in space to commercial companies and other non-governmental organizations. We wrap up the show with a new What’s Up segment with Bruce Betts, where we talk about what could happen if the Gateway lunar space station is canceled, and how that would impact humanity’s dreams for Mars. Discover more at: https://www.planetary.org/planetary-radio/2025-H2M2See omnystudio.com/listener for privacy information.

Alicia Brown from the Commercial Space Federation and Brittany Webster from the American Geophysical Union join the show to discuss NASA’s fiscal year 2026 budget proposal, which aims to slash the agency’s funding by nearly 25%, cut science by 47%, and reduce staffing to levels not seen since 1960. Discover more at: https://www.planetary.org/planetary-radio/fy2026-nasa-budget-discussionSee omnystudio.com/listener for privacy information.

The Giant Magellan Telescope (GMT) is poised to become one of the most powerful ground-based observatories ever built. On June 12, 2025, the U.S. National Science Foundation announced that the GMT will enter its Major Facilities Final Design Phase, bringing it one step closer to full construction. This week on Planetary Radio, host Sarah Al-Ahmed speaks with Rebecca Bernstein, Chief Scientist for the Giant Magellan Telescope Organization and astronomer at the Carnegie Institution for Science, about the groundbreaking technology behind GMT and how it will transform our understanding of the Cosmos. Later in the show, Casey Dreier, chief of space policy at The Planetary Society, returns to discuss his new op-ed in Space News on the White House’s controversial Mars plan, and why a bold vision without political consensus is unlikely to succeed. As always, we wrap up with What’s Up with Bruce Betts, chief scientist at The Planetary Society. Discover more at: https://www.planetary.org/planetary-radio/2025-gmtSee omnystudio.com/listener for privacy information.