Planetary Radio: Space Exploration, Astronomy and Science

Gentry Lee spent nearly five decades at NASA's Jet Propulsion Laboratory, and in that time he helped shape some of the most ambitious missions in the history of space exploration. A new documentary, “Starman,” chronicles his career and the big question that runs through it: is there life beyond Earth? Lee worked on every NASA mission to land on Mars, helped Carl Sagan bring the Univers...

Is the United States really in a new space race with China? Or is that framing missing the bigger picture? In this Space Policy Edition of Planetary Radio, Casey Dreier, chief of space policy at The Planetary Society, sits down with Patrick Besha, former NASA strategic advisor on China, to explore the realities behind China’s rapidly advancing space program. They discuss how China’s po...

NASA has announced a major restructuring of the Artemis program, reshaping the roadmap for returning humans to the Moon. At a February 27 press conference, agency leadership addressed the rollback of Artemis II following post–wet–dress–rehearsal testing and unveiled significant changes to upcoming missions, including shifting Artemis III from a planned lunar landing to a low-Eart...

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 th...

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 Spa...

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, Bil...

Where did Earth’s water come from? In this episode of Planetary Radio, we explore how scientists are answering that question by studying a remarkably well-preserved record of the early Solar System: lunar samples brought back by the Apollo missions. Host Sarah Al-Ahmed is joined by Tony Gargano, postdoctoral fellow at the Lunar and Planetary Institute with the University Space Research Assoc...

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 i...

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....

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 Observation...

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 g...

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...

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 astrophys...

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...

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...

As 2025 comes to a close, Planetary Radio looks back on a year that reshaped space exploration, through stunning discoveries, major milestones, unexpected challenges, and the people who carried science forward through it all. In this episode, Sarah Al-Ahmed, host and producer of Planetary Radio, is joined first by Kate Howells, public education specialist at The Planetary Society, to share results...

2025 was one of the most consequential years for space policy in modern U.S. history. In this special year-in-review episode, Planetary Radio takes a deep dive into what happened behind the scenes in U.S. space policy and advocacy as NASA faced unprecedented proposed cuts to its science programs. With nearly half of NASA’s science budget at risk, dozens of missions threatened, and months of...

It was such a delight to feature work by our own Kate Howells in The Planetary Society’s member book club. We keep Kate busy as our public education specialist, but she found time to write about many of her favorite natural satellites in this richly illustrated edition. Join her and book club host Mat Kaplan for a journey taking us from our own Moon, past Europa, Titan, and many more, and ou...

Thirty years ago, NASA’s Galileo spacecraft became the first mission to orbit Jupiter, opening a new chapter in our exploration of the outer Solar System. Over eight years around Jupiter, Galileo transformed how we understand Jupiter and its moons, revealing a powerful and dynamic planetary system, uncovering evidence for oceans hidden beneath icy worlds, and reshaping the search for life be...

Why do we explore space, and why does science matter in the first place? In this Space Policy Edition rerun, Planetary Society Chief of Space Policy Casey Dreier revisits a deeply influential 2020 conversation with philosopher and ethicist J. S. Johnson-Schwartz, author of The Value of Science and Space Exploration. As debates over NASA’s budget and the future of space science continue to re...

The 2025 International Mars Society Convention convened at the University of Southern California this October for three days of passionate discussion about humanity’s future on the red planet. Speakers explored science, policy, technology, AI, synthetic biology, and the long-term path toward becoming a multi-planet species. In this episode, Mat Kaplan, senior communications adviser at The Pl...

NASA’s twin ESCAPADE spacecraft have finally launched on their journey to Mars. Designed to study how the solar wind interacts with Mars’ patchy magnetic fields and drives the loss of its atmosphere, ESCAPADE is NASA’s first dual-spacecraft mission to the Red Planet and a major milestone for the SIMPLEx program’s small, low-cost planetary explorers. The mission began its vo...

This week on Planetary Radio, we’re sharing a special conversation from our friends at the Smart Girl Dumb Questions podcast. Host Nayeema Raza sits down with The Planetary Society’s Chief of Space Policy, Casey Dreier, to explore one of the most common questions in space exploration: Why does space matter, and is it really worth the cost? Casey breaks down how space exploration impact...

There was a time when almost everyone, from Alexander Graham Bell to the Wall Street Journal, believed there was a supremely intelligent civilization on Mars, one that was probably trying to talk to Earthlings. Most of this belief could be traced to an amateur astronomer and charismatic speaker named Percival Lowell. David Baron tells this story in “The Martians: The True Story of an Alien C...

When his filmmaking career stalled during the pandemic, Toby Lockerbie turned to the one place that had never stopped inspiring him: the Universe. With no background in visual effects, he taught himself the tools needed to transform complex space science into cinematic stories using everyday objects and beautifully crafted visuals to make the Cosmos feel human. His channel, Epic Spaceman, now reac...