Planetary Radio: Space Exploration, Astronomy and Science

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-ceoSee omnystudio.com/listener for privacy information.

Tony Gargano, a lunar researcher at the Lunar and Planetary Institute and NASA Johnson Space Center, explores how Apollo Moon dust preserves clues to Earth’s water origins. He discusses isotopic fingerprints, how the Moon records impacts, lab vaporization experiments, limits on meteorite-delivered water, and why Artemis samples could change the story. Short bonus: George Takei reflects on Star Trek’s influence and the Moon’s future.

Jack Kiraly, director of government relations at The Planetary Society, explains U.S. space policy and congressional authorization basics. He outlines how authorization bills differ from appropriations and why they can lock in decades-long choices. The conversation covers authorizations’ legal power, examples like Europa Clipper and SLS, and why advocates track committee turnover and report language.

Paul Byrne, associate professor of Earth, Environmental, and Planetary Sciences and lead author on a study of Europa, explains why Europa’s seafloor may be surprisingly geologically quiet. Conversations cover how scientists infer hidden ocean-floor conditions, implications for hydrothermal activity and habitability, comparisons with Enceladus, and what upcoming missions could reveal.

Noah Petro, NASA Goddard lab chief and Artemis III project scientist, and Kelsey Young, Artemis Science Flight Operations Lead preparing astronauts for lunar observations, talk lunar return preparations. They discuss Artemis II flyby targets, training astronauts to observe like geologists, the importance of lighting and human description, and science goals for Artemis III at the Moon’s south pole and SPA basin.

After months of uncertainty, NASA science has been spared from the largest proposed budget cuts in the agency’s history. In this episode of Planetary Radio, host Sarah Al-Ahmed unpacks how Congress moved to restore near-full funding for NASA science and what that victory really means for missions, researchers, and the future of space exploration. Sarah is joined by Jack Kiraly, director of government relations at The Planetary Society, and Ari Koeppel, an AAAS science & technology policy fellow at The Planetary Society, to break down what passed in the FY 2026 budget, why the details matter, and how bipartisan support helped protect science programs across planetary science, astrophysics, Earth science, and heliophysics. The conversation also takes an honest look at the costs of the past year, from lost jobs and disrupted missions to shaken morale, and why rebuilding NASA’s scientific workforce will take time, even after this hard-won win. We also look ahead to what comes next as the FY 2027 budget process begins, and why sustained public engagement remains essential to protecting space science. Plus, Bruce Betts, chief scientist of The Planetary Society, joins us for What’s Up, where we discuss the recent early return of astronauts from the International Space Station, what’s known about the situation, and what it means for station operations. Discover more at: https://www.planetary.org/planetary-radio/2026-nasa-science-savedSee omnystudio.com/listener for privacy information.

Famed astrophysicist and science communicator Adam Frank shares his sense of wonder and humor in a live conversation about his excellent new book, “The Little Book of Aliens.” Join Adam and host Mat Kaplan as they explore the origin of life, the search for extraterrestrial intelligence, and whether all those UFO sightings are worthy of deeper investigation. Discover more at: https://www.planetary.org/planetary-radio/book-club-adam-frankSee omnystudio.com/listener for privacy information.

Our Solar System is wrapped in a vast, invisible bubble created by the Sun, a protective region that shields Earth and the planets from much of the radiation that fills our galaxy. But until recently, scientists have only had rough sketches of what this boundary looks like and how it behaves. In this episode of Planetary Radio, host Sarah Al-Ahmed is joined by David McComas, professor of astrophysical sciences at Princeton University and principal investigator of NASA’s Interstellar Mapping and Acceleration Probe (IMAP) and Interstellar Boundary Explorer (IBEX) missions, along with Matina Gkioulidou, a heliophysicist at Johns Hopkins Applied Physics Laboratory, former IMAP-Ultra instrument lead, and current IMAP project scientist and co-investigator. Now stationed at the Sun–Earth L1 Lagrange point, IMAP uses 10 instruments to study the heliosphere — the region where the solar wind collides with material from interstellar space. The mission does this by tracking energetic neutral atoms, particles that travel in straight lines from distant regions of the heliosphere, allowing scientists to map areas of space that spacecraft can’t directly sample. McComas and Gkioulidou explain how IMAP builds on the legacy of Interstellar Boundary Explorer, what makes this mission different, and why understanding the Sun’s influence across space matters not just for fundamental science, but for space-weather forecasting and protecting technology and astronauts closer to home. Discover more at: https://www.planetary.org/planetary-radio/2026-imapSee omnystudio.com/listener for privacy information.

What does it really mean to enter interstellar space, and what have we learned since humanity first crossed the invisible boundary between our Sun and the stars? In this episode of Planetary Radio, we explore the science of the heliosphere and the realm beyond with Linda Spilker, project scientist for the Voyager mission at NASA Jet Propulsion Laboratory. Drawing on decades of experience with the twin spacecraft, Spilker shares how Voyager reshaped our view of the Solar System’s outer frontier, from the nature of the heliopause to the unexpectedly rich structure of the local interstellar medium. We unpack what Voyager 1 and Voyager 2 have taught us about charged particles, magnetic fields, and cosmic rays beyond the Sun’s protective bubble, and why those measurements have upended earlier ideas about where the Solar System truly ends. Spilker also reflects on the mission’s extraordinary longevity, the ingenuity required to keep the spacecraft communicating across the vastness of space, and what Voyager’s legacy means for future journeys between the stars. Then, in What’s Up, Bruce Betts, chief scientist at The Planetary Society, places Voyager in context, showing how long-lived missions shape the bigger picture of space science and why observing longer can lead to some of our most profound discoveries. Discover more at: https://www.planetary.org/planetary-radio/2026-voyagers-and-the-heliopauseSee omnystudio.com/listener for privacy information.

Marcia Smith, the founder and editor of Space Policy Online, joins the show and revisits a conversation we had one year ago, recorded just weeks before the second Trump administration took office. That episode, “The Challenges of Change at NASA,” explored the institutional and political roadblocks to radical change at the U.S. space agency. A lot has happened since that show, including DOGE, mass staff departures, a draconian budget cut proposal, a dramatic shift toward sending humans to Mars, and the rapid departure of 20% of NASA's workforce. But at the end of the year, much remains the same. The SLS and Orion programs continue unchanged, with funding locked in through 2032. The humans-to-Mars policy has effectively vanished; returning U.S. astronauts to the Moon, to stay, is again centered within civil space policy. NASA's science missions, though still facing a serious budgetary threat, have not gone away. So, did we see real change at NASA? And to what end? Or was it merely disruption masquerading as change? Marcia Smith and host Casey Dreier revisit their original analysis and discuss what they got wrong, what they got right, and what surprised them about 2025 in civil space policy. Discover more at: https://www.planetary.org/planetary-radio/spe-2025-a-year-of-disruption-and-change-at-nasaSee omnystudio.com/listener for privacy information.