Clyde Tombaugh
The Astronomer Who Discovered Pluto
Clyde Tombaugh found Pluto by comparing photographic plates one pair at a time, searching for a tiny point that moved against the stars.
Lived
1906–1997
Known for
Discovery of Pluto
Field
Astronomy
TransitSatellite connection
Pluto and New Horizons
Choose a reading level
Each level uses the same core historical facts with a different depth of explanation.
Biographical details
- Born
- 1906-02-04 - Streator, Illinois, United States
- Died
- 1997-01-17 - Las Cruces, New Mexico, United States
- Education
- University of Kansas (degrees earned after the discovery of Pluto)
Chapter 1
Where the Story Begins
Tombaugh grew up on farms in Illinois and Kansas and built his own telescopes after his family could not afford expensive equipment.
Chapter 2
The Challenge
Find the predicted “Planet X” in a sky crowded with millions of stars and photographic defects.
Chapter 3
The Turning Point
In 1930 Tombaugh identified Pluto on plates taken at Lowell Observatory.
Chapter 4
What Changed
His discovery added a new world to the known Solar System and later became part of the story of the Kuiper Belt.
Chapter 5
TransitSatellite Connection
New Horizons carried a small portion of Tombaugh’s ashes past Pluto in 2015, linking his discovery directly to modern spacecraft exploration.
Key facts
- Born on 1906-02-04 in Streator, Illinois, United States.
- Known for: Discovery of Pluto
- Primary field: Astronomy
- His discovery added a new world to the known Solar System and later became part of the story of the Kuiper Belt.
- New Horizons carried a small portion of Tombaugh’s ashes past Pluto in 2015, linking his discovery directly to modern spacecraft exploration.
Vocabulary
Discussion questions
- Why was the challenge facing Clyde Tombaugh difficult at the time?
- What evidence, calculation, observation, engineering decision, or leadership choice changed the story?
- Which modern spacecraft, mission, or tracking tool best shows this legacy?
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