Planetary Radio: Space Exploration, Astronomy and Science

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 int...

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...

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 c...

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&rsq...

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...

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 ...

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 th...

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,...

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-discussion

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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 Organi...

Few writers have captured the wonder of science through storytelling as powerfully as Dava Sobel. In this episode, we celebrate her remarkable career and her recent honor as the recipient of The Planetary Society’s 2025 Cosmos Award for Outstanding Public Presentation of Science. Mat Kaplan, senior communications advisor at The Planetary Society, sits down with Sobel for a conversation about the human lives behind great scien...

What does it take to turn a love of space into a global career in science journalism? Sarah Cruddas has done just that. With a background in astrophysics and a passion for storytelling, she’s become a leading voice in space media, covering rocket launches, interviewing astronauts, and writing books that bring the Cosmos down to Earth. In this episode, Sarah shares her path from the U.K. to the front lines of space communicati...

Former NASA Chief Economist Akhil Rao explains why NASA needs economic expertise to navigate the complex—and often misunderstood—market forces that will determine the success or failure of its private partnerships. As NASA relies ever more on commercial companies to enable its own exploration efforts, it is imperative, Rao believes, to provide clear-eyed perspectives that highlight the challenges and solutions required ...

The White House has released its Fiscal Year 2026 congressional budget justification for NASA, and the implications are staggering. If enacted, this proposal would slash NASA’s science program funding by nearly half, cancel dozens of active and upcoming missions, and reduce the agency’s workforce by one-third. Sarah Al-Ahmed is joined by Jack Kiraly, The Planetary Society’s director of government relations, to exa...

Volcanoes aren’t just an earthly phenomenon. They’re found all across the Solar System. In this compilation episode of Planetary Radio, we explore volcanic and geothermal activity on planets, moons, and distant dwarf planets. You’ll hear from Rosaly Lopes, Nick Schneider, Rae Paoletta, Robbie Herrick, Scott Hensley, and Christopher Glein as they share insights into everything from lava flows on Venus and eruptions...

As debates over NASA's future heat up, questions about the value of space exploration are popping up everywhere. This week on Planetary Radio, we're tackling the tough questions head-on with The Planetary Society's staff, including Casey Dreier, chief of space policy, and Ambre Trujillo, digital community manager. They break down the biggest misconceptions about space science, public versus private investment, and why exploration s...

This week on Planetary Radio, we explore the decades-long journey of Kosmos 482, a Soviet-era Venus probe that spent 53 years orbiting Earth before its dramatic return on May 10, 2025. Ben Fernando, a postdoctoral researcher in seismology and planetary science at Johns Hopkins University, joins us to explain the history of Kosmos 482 and how seismology and acoustic sensors are helping scientists detect and locate objects impacting ...

TOI-270 d is revealing secrets about the most common type of planet in our galaxy, sub-Neptunes. Sarah Al-Ahmed is joined by planetary geochemist Chris Glein from the Southwest Research Insitute to discuss his team’s new analysis of its atmosphere, using data from JWST and insights from Earth analogs. Then, The Planetary Society’s Director of Government Relations, Jack Kiraly, breaks down the historic budget cuts propos...