Episodes

  • Chicxulub: The Impact That Changed Life on Earth

    Chicxulub: The Impact That Changed Life on Earth
    Sep 16 2026
    Sixty-six million years ago, an asteroid struck near the Yucatan and altered the course of life. Follow the evidence linking Chicxulub to the K-Pg extinction, the rapid collapse of a vast crater, the darkness and cooling that followed, and the ocean-drilling cores that record destruction and recovery. Inside this episode: - The iridium boundary and the search for an impact crater - How the Chicxulub peak ring formed - What happened during the first day - Darkness, cooling, food-web collapse, and extinction - Drilling the buried crater and tracing recovery Sources include International Ocean Discovery Program Expedition 364 records, peer-reviewed impact and climate studies, and geological syntheses. This episode is a researched narrative summary. Historical records may be incomplete, translated differently, or interpreted differently by scholars. We distinguish documented facts, estimates, disputed interpretations, and later stories where material. Corrections are logged and incorporated into future editions. Follow Earth Before Humans for more researched chapters from the planet's deep past.
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    10 mins
  • The Great Oxidation: When Microbes Changed the Sky

    The Great Oxidation: When Microbes Changed the Sky
    Sep 16 2026
    For much of early Earth, the atmosphere contained almost no free oxygen. Follow the evidence for the Great Oxidation Event, when microbial photosynthesis and a changing balance of chemical sinks allowed oxygen to persist, reshaping rocks, climate, oceans, and the possibilities for later life. Inside this episode: - Earth before oxygen accumulated in the atmosphere - How oxygenic photosynthesis changed the planetary balance - Sulfur isotopes, red beds, iron formations, and other evidence - Why oxygen sources and sinks mattered - Climate connections and the stepwise oxygenation of Earth Sources include peer-reviewed geochemistry and Earth-system research, NASA technical reviews, and published studies of early atmospheric oxygen. This episode is a researched narrative summary. Historical records may be incomplete, translated differently, or interpreted differently by scholars. We distinguish documented facts, estimates, disputed interpretations, and later stories where material. Corrections are logged and incorporated into future editions. Follow Earth Before Humans for more researched chapters from the planet's deep past.
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    11 mins
  • Burgess Shale: A Lost Ocean Preserved in Stone

    Burgess Shale: A Lost Ocean Preserved in Stone
    Sep 16 2026
    High in the Canadian Rockies, stone preserves an ocean community about 508 million years old. Explore how the Burgess Shale captured soft-bodied animals, what Charles Doolittle Walcott collected there, and why fossils such as Opabinia, Hallucigenia, and Anomalocaris transformed our picture of Cambrian life. Inside this episode: - The 1909 discovery in Yoho National Park - How rapid burial preserved soft anatomy - The unfamiliar animals of the Cambrian ocean - What the fossils reveal about food webs and seafloors - Why scientific reconstructions continue to change Sources include Parks Canada records, Smithsonian National Museum of Natural History collections, Walcott field notes, and paleobiology research. This episode is a researched narrative summary. Historical records may be incomplete, translated differently, or interpreted differently by scholars. We distinguish documented facts, estimates, disputed interpretations, and later stories where material. Corrections are logged and incorporated into future editions. Follow Earth Before Humans for more researched chapters from the planet's deep past.
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    11 mins