3 Billion Years Ago: Was Mars Alive?

What does a NASA authorization bill actually do, and why does it matter? In this episode of Space Policy Edition, we dig into one of the most misunderstood but powerful tools Congress uses to shape the future of U.S. space exploration. Host Casey Dreier, chief of space policy at The Planetary Society, is joined by Jack Kiraly, the Society’s director of government relations, for a deep dive into how NASA authorization bills work, how they differ from appropriations, and why they can have decades-long consequences for science missions, human spaceflight, and planetary defense. The discussion also reflects on a major recent win for space advocates: Congress’s bipartisan decision to protect NASA science funding. Discover more at: https://www.planetary.org/planetary-radio/spe-what-is-a-nasa-authorization-billSee omnystudio.com/listener for privacy information.

6 Feb 1h

What if Europa’s seafloor isn’t alive with activity after all? This week on Planetary Radio, host and producer Sarah Al-Ahmed explores new research that reframes how scientists think about one of the Solar System’s most intriguing ocean worlds. Sarah is joined by Paul Byrne, associate professor of earth, environmental, and planetary sciences at Washington University in St. Louis. Paul is the lead author of a new study suggesting that the seafloor beneath Europa’s global ocean may be geologically quiet today, potentially lacking the hydrothermal activity often associated with habitable environments on Earth. Together, they discuss how scientists investigate places we can’t yet observe directly and why Europa remains a compelling world to explore regardless of what we find. Then, Bruce Betts, chief scientist of The Planetary Society, joins us for What’s Up to explain why Saturn’s moon Enceladus shows strong evidence for active hydrothermal vents beneath its icy crust, offering a fascinating contrast between two ocean worlds. Discover more at: https://www.planetary.org/planetary-radio/2026-europas-quiet-seafloorSee omnystudio.com/listener for privacy information.

4 Feb 1h 2min

Humans are preparing to return to the Moon. On this episode of Planetary Radio, host Sarah Al-Ahmed is joined by Kelsey Young and Noah Petro, two of the scientists helping turn humanity’s return to the Moon into reality. Kelsey Young is a research space scientist at NASA Goddard Space Flight Center and serves as the Artemis Science Flight Operations Lead. She also leads the Lunar Observations and Imaging Campaign for Artemis II, defining what astronauts will observe, document, and study as they fly around the Moon for the first time in more than 50 years. Noah Petro is the lab chief of the Planetary Geology, Geophysics, and Geochemistry Laboratory at NASA Goddard and the former Project Scientist for the Lunar Reconnaissance Orbiter. He also serves as the Project Scientist for Artemis III, helping shape the science behind humanity’s first lunar footsteps of the 21st century. Together, they discuss how Artemis II and Artemis III build on decades of lunar science, how astronauts are being trained to observe the Moon like geologists, and why the Moon’s south pole is such a compelling destination for future exploration. Then, we wrap up with What’s Up, where Bruce Betts, chief scientist of The Planetary Society, shares the story of the first and so far only professional geologist to walk on the Moon. Discover more at: https://www.planetary.org/planetary-radio/2026-artemis-ii-and-iiiSee omnystudio.com/listener for privacy information.

28 Jan 1h 4min

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.

21 Jan 1h 1min

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.

16 Jan 44min

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.

14 Jan 56min

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.

7 Jan 58min

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.

2 Jan 1h 11min