AZ: The History of Arizona podcast · David Rookhuyzen

Episode 223: Pluto

·39 min·2 clips

Tombaugh tells Slipher, 'I have found your planet X,' after Lamplin confirms the plates.

1. AZ: The History of Arizona podcast Episode 223, “Pluto,” centers on Lowell Observatory in Flagstaff and the 1930 discovery of Pluto. 2. Host David Ruckhausen narrates the story as a history episode, and the names Percival Lowell, V.M. Slipher, Robert Low Putnam, and Clyde Tombaugh drive the plot. 3. The episode asks how Lowell Observatory moved from a stalled search for Planet X to the moment Tombaugh found an object beyond Neptune. 4. After Percival Lowell died in 1916, legal battles with Constance Lowell slowed the observatory, and Guy Lowell later died in 1927 while on vacation in Europe. 5. Robert Low Putnam became trustee, backed V.M. Slipher as director, and decided Lowell Observatory should resume the hunt for Lowell’s hypothetical ninth planet. 6. The observatory built the Lawrence Lowell Telescope from three 13-inch glass disks bought in 1925 and paid for with Abbot Lawrence Lowell’s $10,000 gift. 7. Slipher directed construction of the Slipher Building west of the main administration building, and Stanley Sykes helped build the dome and mount. 8. Clyde Tombaugh enters the story after sending sketches of Mars and Jupiter from Kansas to Lowell Observatory, where Slipher questions his training and ability to work in cold domes. 9. Tombaugh was born near Streeter, Illinois, on February 4th, 1906, grew up on a farm, and spent nights reading the Bible, trigonometry, Latin, and Greek by kerosene lamp. 10. His uncle Lee introduced him to astronomy with a 20-year-old 3-inch telescope, then a shared 5.5-inch Sears Roebuck refractor opened up more of the sky. 11. Tombaugh built a 7-foot-long box telescope with an 8-inch mirror, dug a 24-foot by 8-foot root cellar for mirror testing, and later produced a 7-inch telescope for Uncle Lee. 12. He then built a 9-inch reflector whose mount used parts from an old 1910 Buick and a cream separator, and the Wichita firm told him he had a job waiting there in a year. 13. A 1928 hailstorm destroyed his family’s wheat and oat crop, and his calculations for a neighbor’s granary convinced one farmer to tell him, “You’re a born mathematician.” 14. On January 2, 1929, Lowell Observatory formally offered Tombaugh a room, observational work, janitorial duties, and other labor, and he chose Flagstaff over the Wichita telescope job. 15. Tombaugh arrived in Flagstaff on January 15, 1929, helped with breakfast runs, mail, furnace coal, public tours, and snow removal from the 42-inch telescope dome. 16. The 13-inch telescope arrived on February 11, 1929, became an astrograph capable of reaching 17th magnitude, and produced 14x17-inch plates covering tens of thousands of stars each. 17. On April 6, 1929, Tombaugh began the systematic search for Planet X, a process described as long, boring, and laborious because it required repeated exposures of the same sky. 18. During the summer, Slipher handed Tombaugh the blinking work, and Tombaugh spent hours comparing hundreds of thousands of dots until the object appeared on the January 23rd and January 29th plates. 19. The episode uses a measured, detail-heavy storytelling style with direct quotes from Levy, The Explorers of Mars Hill, and Tombaugh himself. 20. Listeners interested in Arizona astronomy and Flagstaff history will get the most from it, while people wanting a short, fast-moving science story may skip it.

As heard by us

Pluto's 2006 reclassification becomes a clear Arizona story about memory, science, and Tombaugh's unlikely arrival.

Pluto's 2006 reclassification lands as more than a footnote here; it becomes a local story about how a familiar label can feel permanent until it is not.

Read the full review in PlayNext →

Why you'd press play

You want the backstory behind the planet everyone thought they knew.

Read the full recommendation in PlayNext →

Listen to the show on

Apple Podcasts Spotify

Play clips from this episode More from AZ: The History of Arizona podcast