Planetary Radio: Space Exploration, Astronomy and Science · The Planetary Society

Book Club Edition: The Little Book of Aliens by Adam Frank

·44 min·2 clips

Jason Wright’s team found all SETI searches amount to a "hot tub" compared with the sky’s ocean.

Adam Frank returns to talk aliens, with Matt Kaplan steering a Book Club visit around The Little Book of Aliens. The conversation is friendly, but it does not stay fuzzy for long. Frank moves the alien question toward evidence: technosignatures, the observable traces a technological civilization might leave behind on a planet. Atmospheric chemistry gets the fun job here. Chlorofluorocarbons are the example, because if they showed up in an atmosphere, they could point to technology. Frank says a planet with ten times our current chlorofluorocarbon level could be detectable even by the James Webb Space Telescope. That makes pollution feel less like a dead-end warning and more like a strange clue, especially because the same molecules could be put there on purpose. Mars gives the idea a practical hook. Frank explains that someone trying to warm Mars might pump chlorofluorocarbons into the atmosphere as a terraforming tool. So the search is not only about alien messages. It is also about whether terraformed planets, or planets being terraformed, could be spotted from hundreds of light years away. Kaplan keeps the big ideas easy to follow while Frank talks detection, greenhouse gases, and planetary engineering. The break brings in LeVar Burton's Planetary Academy message, connecting that same curiosity to children and families through solar-system mail packages, activities, experiments, and games.

As heard by us

A measured, evidence-first look at how alien life might leave a detectable trace.

Adam Frank uses the book-club setting to frame alien life as a practical problem: what would a technological civilization leave behind, and how could it be found?

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Why you'd press play

You want aliens discussed as a scientific problem, not a cartoon mystery.

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