How Clyde Tombaugh Found Pluto? - A Biography Of The Famous Astronomer

How Clyde Tombaugh Found Pluto? -  A Biography Of The Famous Astronomer
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Born: Clyde William Tombaugh was born on February 4, 1906 in Streator, Illinois. Tombaugh was the eldest of six children in a poor family. His father, Muron Tombaugh was a farmer and his mother was Adella Chritton Tombaugh.

Education: Though Tombaugh was an excellent student, when he graduated from Burdett High School in 1925, there was little chance of continuing his education. The families wheat crop had been destroyed by hail and their was no money to send Tombaugh off to school. Eventually, in the fall of 1932, Tombaugh was able to start school after receiving a scholarship from the University of Kansas. Tombaugh earned a bachelor of science in astronomy in 1936 and completed his masters of science in astronomy in 1939.


• 1929 to 1945: Junior astronomer at Lowell Observatory, conducting a photographic survey.

• 1943 to 1945: During World War II, teacher of physics at Northern Arizona University, while also teaching navigation at the school for the U.S. Navy.

• 1946 to 1955: A civilian astronomer and optical physicist for the U.S. Army at White Sands Missile Range. Tombaugh developed methods of optically tracking rockets in flight and improving their performance.

• 1955 to 1973: Astronomy professor at New Mexico State University working on a federally funded search for near-earth satellites.

Publications: As a professional astronomer and discover of Pluto, Clyde Tombaugh published a number of papers, reports and articles. In 1980, Tombaugh published Out of the Darkness: The Planet Pluto co-authored with Patrick Moore. The book was an autobiographical look at his most well known scientific accomplishment.

Death: January 17, 1997, Tombaugh passed away at his home in Las Cruces, New Mexico.


Major Accomplishment - How Clyde Tombaugh Found Pluto

Percival Lowell-observing Mars from the Lowell Observatory

Clyde Tombaugh was only a simple farm boy with a high school diploma when he made one of the most important discoveries in the history of astronomy. Clyde had been hired to work at the Lowell Observatory in Flagstaff Arizona, operating its newly built 13 inch astrograph to search for a planet out further than Neptune. Percival Lowell, astronomer and the founder of the Lowell Observatory was sure that an as yet undiscovered gas giant was responsible for perturbations or wobbles in the orbit of Neptune. Until his death, Lowell searched in vain for the mysterious Planet X using his own rough calculations.

To find the planet, Tombaugh used a systematic approach instead. He spent thousands of hours examining some two thirds of the night sky and painstakingly taking pictures of one small area at a time. Several days later, he would take another picture of the same small area. Then using a Blink-Comparator he would examine and compare the two pictures. The device allowed for rapid back and forth viewing of two pictures, making it easier to see moving lights, which might indicate a planet. On February 18, 1930 after only 10 months on the job, Tombaugh discovered Pluto. The official announcement was made on March 13, 1930, Lowell’s birthday. The news was quickly met with enthusiasm from the general public and astronomers.

Pluto System

Though it was determined that the small icy planet had a mass too small to account for the gravitational pull on Neptune the news was still met with praise and Tombaugh became an international celebrity among the scientific community and the general public. It was not until decades later that a scientist discovered that the wobbles in Neptune’s orbit were actually due to uncalibrated equipment. Tombaugh died before Pluto was reclassified as a dwarf planet in 2006. His discovery would help open up exploration into the Kuiper Belt in the outer reaches of the solar system and the knowledge that small dwarf planets like Pluto are common and number in the thousands.

Other Accomplishments

Though he will always be best remembered for his discovery of Pluto, Clyde Tombaugh had a career full of highs. Other findings of his made at the observatory included a super-cluster of galaxies, galaxy clusters, star clusters, a nova, hundreds of previously unknown of asteroids and two comets. Among these discoveries are: Comet C/1931 AN, (which currently has an unknown orbit), Asteroids 2839 Annette, 5701 Baltuck, 3775 Ellenbeth, 3310 Patsy and open star clusters Tombaugh 1 and Tombaugh 2. He also correctly theorized that galaxies are distributed in clumps instead of the more accepted belief at the time that they are evenly distributed.

While a civilian employee at the Ballistics Research Lab at the White Sands Missile Range, Tombaugh focused on optical instrumentation development. Using his knowledge of optical design Tombaugh created specialized telescopes and collected scientific data of missiles that helped make the experimental missile tracking program a success. Research into natural near-earth satellites followed while at the New Mexico State University. His findings that nothing was there helped give the green light for space travel.


A Launch at White Sands Missile Range

Interesting Facts


• Tombaugh got his first glimpse at the sky through his uncle’s telescope. As he was unable to afford powerful telescopes with the image quality he needed, Tombaugh began making his own by the time he was 20.

• The amateur telescope maker ground and polished his own mirrors. One of his telescopes featured a crankshaft made of parts from a 1910 Buick. Tombaugh used one of his homemade telescopes to make a detailed drawing of the positions of Mars and Jupiter. After sending it to Lowell Observatory for feedback, Tombaugh was offered a job.

• Growing up in a rural environment without access to a large library collection or observatories, Tombaugh taught himself much of the practical knowledge that would help him find Pluto. He taught himself geometry and trigonometry and read every book and science publication he could find related to astronomy.

• When Tombaugh discovered the planet Pluto, he had not yet even gone to college. In fact, at 16 Tombaugh had to drop out of high school for a year in order to help prepare the families wheat crop.

• With his discovery of Pluto, the famous astronomer became the first American and the only person in the Western Hemisphere to discover a planet.

Artist’s conception of New Horizons at Pluto

• After Tombaugh enrolled in college at the University of Kansas, he was denied access to the beginner’s course in astronomy. The astronomy professor believed that having a student in the class who had already discovered a planet would be a bit disconcerting.

• To honor the legacy of Clyde Tombaugh, NASA included a small sample of his ashes on the New Horizons robotic space probe. New Horizons was launched in January 2006 on a mission to explore Pluto and the Kuiper Belt. The probe will reach Pluto in 2015 before continuing on - making Tombaugh’s remains the first to venture into interstellar space.