LAS CRUCES, N.M. -- Clyde W. Tombaugh, discoverer of the planet Pluto and father of the astronomy research program at New Mexico State University, died Friday, Jan. 17, at his home in Las Cruces. He was 90.
"He was truly one of the great men of science," said Jack Burns, associate dean of arts and sciences and former astronomy department head at NMSU.
Tombaugh was 24 years old when he made world news in 1930 by discovering the elusive ninth planet using a photographic telescope at Lowell Observatory in Arizona.
He remained active long after retiring as a professor emeritus in 1973, lecturing on an occasional basis and going to his office regularly. In the 1980s, he went on an extensive lecture tour to raise money for an astronomy endowment at NMSU.
Tombaugh is survived by his wife, Patsy; son, Alden Tombaugh, of Las Cruces; daughter, Annette Tombaugh, also of Las Cruces; five grandchildren and eight great-grandchildren.
Born on Feb. 4, 1906, on a farm near Streator, Ill., Tombaugh moved with his family to a farm near Burdett, Kansas, during his high school years. He shared his father's keen amateur interest in astronomy, and when he wanted a telescope more powerful than his 2 1/4-inch Sears Roebuck model, he began grinding mirrors and making his own.
Using a hand-made 9-inch telescope, he made meticulous sketches of Jupiter and Mars and sent some of them to the Lowell Observatory. He thought he might get some advice from the professionals. Instead he was offered a job. It happened that the observatory was looking for a good amateur astronomer who could operate a new photographic telescope.
Tombaugh was hired in 1929 as a junior astronomer to join in the search for a "Planet X" beyond Neptune, a search begun in 1905 by Percival Lowell. Working through the nights in a cold, unheated dome, he made pairs of exposures of portions of the sky with time intervals of two to six days. These were scrutinized under a device called a Blink-Comparator in hopes of detecting a small shift in position of one of the hundreds of thousands of points of light -- the sign of a planet among a field of stars.
On the nights of Jan. 23 and 29, 1930, Tombaugh made two such photographs of the region of the star Delta Geminorum. On the afternoon of Feb. 18, comparing the plates with the Blink-Comparator, he detected the telltale shift of a faint, starlike image. The discovery was confirmed with subsequent observations and announced to the world on March 13, 1930.
Tombaugh continued searching the skies at Lowell Observatory over the next 13 years, with time out for a college education. No more planets showed up, but he discovered six star clusters, two comets, hundreds of asteroids, several dozen clusters of galaxies and one super-cluster.
During those same years, he entered the University of Kansas on a scholarship (1932), married Patricia Edson of Kansas City (1934), earned his bachelor's degree in astronomy (1936) and went on to get his master's (1939).
After teaching at Arizona State College (now Northern Arizona University) and the University of California at Los Angeles, Tombaugh moved to New Mexico in 1946 to become chief of the Optical Measurements Branch in the Ballistics Research Laboratory at White Sands Missile Range, where German V-2 rockets were being tested. He came to New Mexico State University in 1955 and started the Planetary Group, an astronomy research program.
He was instrumental in designing and obtaining funding for the university's Tortugas Mountain Observatory, a 24-inch telescope that captured its first images in 1967 and is still in service taking data for the National Aeronautics and Space Administration.
Tombaugh was largely responsible for the astronomy program becoming a separate department at NMSU in 1970. Today the department is a member of the Astrophysical Research Consortium, which owns and operates the Apache Point Observatory in New Mexico's Sacramento Mountains. NMSU manages the observatory.
Tombaugh remained active long past retirement and never lost his passion for stargazing. When the Smithsonian Institute asked if it could have for its museum the telescope he made in 1928, "I told them I was still using it," he said in an interview. The 9-inch telescope, with which he made the drawings that impressed the Lowell Observatory staff, was built with parts of discarded farm machinery and a shaft from his father's 1910 Buick. Tombaugh ground the mirrors himself.
Until frail health prevented it, Tombaugh continued observing the heavens through that 9-inch telescope and a larger one he made himself, from his back yard in the Mesilla Park community of Las Cruces.
While he was in his 80s, Tombaugh toured the United States and Canada with his wife, Patsy, giving 75 lectures during a three-year period to raise money to bring astronomers to NMSU for post-doctoral research. The Tombaugh Scholars Fund now is a permanent endowment.
"We have 120 applicants for the Tombaugh Scholar position that is open for the fall," said NMSU's Walterbos. "That's an indication of how important this scholarship is."
Tombaugh, the former farm boy with a fondness for corny jokes and puns, delighted in recounting the tale of his discovery of Pluto, which he compared to finding a needle in a haystack. It was tedious work but better than pitching hay on his father's farm, he liked to say: "I'd had my hay day."
By the time he retired, he and his NMSU astronomy staff had confirmed the rotation period of Mercury on its axis, determined the vortex nature of Jupiter's Great Red Spot, and developed a new photographic technique for the small Earth satellites search he was supervising.
Of the decades of discovery since he made the history books, and the thousands of hours spent at his telescopes, Tombaugh often said: "I've really had a tour of the heavens."
Hamilton Amateur Astronomers
Maintained by Rob Roy