On the night of November 12 to 13, 1833, observers across North America watched up to 100,000 or more meteors per hour tear silently across the sky. This episode explores the Leonids, the annual meteor shower born from comet 55P/Tempel-Tuttle, and explains why its retrograde orbit produces head-on collisions at 70 kilometers per second, the fastest of any annual shower, turning a half-gram pebble into a meteor as bright as the brightest star.

The hosts break down why some years bring a gentle shower and others a storm, how young dense dust ribbons differ from diffuse older trails, and how Jupiter’s gravity plus the Poynting-Robertson and Yarkovsky effects reshape those trails over time. They revisit the cultural shock of 1833, from the Lakota winter count and a Cheyenne peace treaty to accounts by Harriet Tubman, Frederick Douglass, Joseph Smith, and Abraham Lincoln, then follow Denison Olmsted’s crowdsourced observations that moved meteors from meteorology into astronomy, the 1899 dud, the 1966 storm of 144,000 per hour, and the 1999 computer models that finally predicted outbursts to within ten minutes.

• Why kinetic energy scaling with velocity squared makes tiny Leonid particles so brilliantly bright
• How the radiant point in Leo revealed that meteors travel in parallel lines from outer space
• Why Jupiter pulled the expected 1899 dust lane just out of Earth’s path
• How scientists tracked Leonid impacts on the Moon by watching its sodium tail grow
• Why smaller outbursts are predicted for 2033 or 2034 but a true 1833-scale storm may not be possible until 2099