More than three billion miles from Earth, an aluminum container aboard the New Horizons spacecraft holds a portion of Clyde Tombaugh's ashes. This deep dive traces how a self-taught farm boy whose college fund was destroyed by a 1928 hailstorm became one of the great observational astronomers of the twentieth century, discovered Pluto at age 24, and later mapped structures a billion light years across.

The episode covers the homemade telescope he built by grinding a mirror inside a 24-foot trench dug to control temperature, the sketches of Mars and Jupiter that earned him a job at Lowell Observatory in 1929, the grueling blink comparator search that ended on February 18, 1930, and the naming of Pluto by an 11-year-old girl. It then follows his discovery of the Perseus-Pegasus filament, the 2006 reclassification debate, his UFO sightings in  ...