In 1930, a 24-year-old farm boy from Kansas made one of astronomy's most captivating discoveries—a tiny, distant world at the edge of our solar system. For 76 years, Pluto held the title of our ninth planet, capturing imaginations and inspiring wonder about the cosmic frontier.

Tonight's episode follows the remarkable story of Clyde Tombaugh's methodical search through millions of stars, guided by mathematical predictions that traced back to the same calculus revolution we explored in Episode 1. Using a "blink comparator" and extraordinary patience, Tombaugh spotted the faint dot of light that would become the most beloved celestial object in our solar system.

But Pluto's story didn't end with discovery. We'll explore how an 11-year-old girl from Oxford named this distant world, how our understanding of it evolved from Earth-sized planet to tiny ice ball, and why the 2006 decision to reclassify it as a "dwarf planet" sparked passionate debate that continues today.

From the loneliness of the night shift at Lowell Observatory to the stunning heart-shaped plains revealed by NASA's New Horizons mission, Pluto's tale is one of human curiosity, scientific evolution, and our changing relationship with the cosmos. It's the perfect story for minds ready to drift toward sleep while pondering the mysteries at the edge of everything we know.

Whether you stay awake for the full journey to the outer solar system or drift off while imagining Pluto's slow dance with its moon Charon, you'll absorb something wonderful about discovery, determination, and the ever-changing nature of scientific understanding.

Sweet dreams, space explorers.