Planetary Radio: Space Exploration, Astronomy and Science

On the night of Oct. 5, 1923, Edwin Hubble spotted a variable star in Andromeda from Mt. Wilson Observatory above Pasadena, California, proving that our galaxy is just one of countless others in the Universe. Now, California Rep. Judy Chu, co-chair of the Planetary Science Caucus, has introduced a resolution in the U.S. House of Representatives supporting the designation of Oct. 5 as National Beyond the Milky Way Day in the United States. John Mulchaey, president of Carnegie Science, and Jess Soto, Carnegie Science’s public engagement specialist, join Planetary Radio to share the story of the discovery and the push for national recognition. We also bring you highlights from the Oct. 13 ceremony at Carnegie’s Hale Library, along with conversations with Rep. Chu, Planetary Society CEO Jennifer Vaughn, and astrophysicist Laura-May Abron. Asa Stahl, our public outreach astronomer, shares how you can vote in The Planetary Society’s Best of 2026 Awards. Then Bruce Betts, our chief scientist, explains why it took humanity so long to realize Andromeda was a galaxy and how you can see it for yourself.
Discover more at: https://www.planetary.org/planetary-radio/2026-beyond-the-milky-way-day
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NASA’s Perseverance rover has driven farther than any other vehicle on another world. On Oct. 11, 2026, its odometer reached 45.22 kilometers (28.10 miles), passing the record Opportunity spent about 15 years setting. Perseverance did it in about five and a half years. To celebrate, we’re revisiting previous Planetary Radio host Mat Kaplan’s 2021 conversation with Vandi Verma, chief engineer of robotic operations for Perseverance at NASA’s Jet Propulsion Laboratory. She explains AutoNav, the self-driving system that has carried the rover more than 90% of the way, and the careful work of collecting rock samples on Mars. Host Sarah Al-Ahmed catches us up on what’s happened since and marks 25 years of Mars Odyssey. Then stick around for a vintage What’s Up with Mat and Chief Scientist Bruce Betts.
Discover more at: https://www.planetary.org/planetary-radio/2026-perseverance-distance-record
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Every two years, The Planetary Society funds research through our STEP Grants (Science and Technology Empowered by the Public). This year, all three winning projects focus on small bodies in our Solar System, like asteroids and trans-Neptunian objects. Each one tackles a different piece of the same challenge: As we discover more and more small bodies, how do we characterize them, and how do we make sure the whole community can build on what we learn? Nick Moskovitz and his team at Lowell Observatory, including instrumentation lead Ryan Hamilton and instrument designer Katie Breeland-Newcomb, are building a low-cost, replicable polarimeter to break through the size ambiguity that makes it hard to tell a small, bright asteroid from a large, dark one. Miguel Alarcón of Light Bridges is expanding AsteroidDB, a database of over 15 million photometric measurements, so researchers and citizen scientists can pool their data. And Mike Kretlow of the German Center for Astrophysics is scaling up CORA, his stellar occultation prediction and archive platform, to handle the tens of thousands of new discoveries expected from the Vera Rubin Observatory. Plus, Bruce Betts joins for What’s Up and to look at the origins of the STEP Grant program.
Discover more at: https://www.planetary.org/planetary-radio/2026-step-grant-winners
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Leroy Chiao was one of the youngest astronauts ever selected. He would spend 229 days in low-Earth orbit, command the International Space Station, and perform three spacewalks. His book, “Dinner with an Astronaut,” chronicles his journey from Chinese American kid born in Milwaukee, Wisconsin to the literal heights of space achievement. Leroy also shares his thoughts about topics as diverse as engineering, Chinese food, and UFOs/UAPs in this entertaining conversation with The Planetary Society’s Mat Kaplan.
Discover more at: https://www.planetary.org/planetary-radio/book-club-leroy-chiao
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Japan’s Martian Moons eXploration mission, MMX, is about to set out for Phobos and Deimos, the two small moons of Mars. If all goes well, it will bring the first-ever sample from the Martian system back to Earth. Asa Stahl, public outreach astronomer at The Planetary Society, explains why these strange little moons are still such a mystery and what a piece of Phobos could reveal. Then Kris Zacny, vice president and senior research scientist at Honeybee Robotics, tells the story of PlanetVac, a sampler that Planetary Society members helped get off the ground more than a decade ago. From its first tests in a vacuum chamber to the surface of the Moon aboard Firefly Aerospace’s Blue Ghost lander, PlanetVac has come a long way, and its descendant is now headed for Phobos. Plus, Bruce Betts, chief scientist at The Planetary Society, joins us in What’s Up.
Discover more at: https://www.planetary.org/planetary-radio/2026-mmx-planetvac
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