Clyde Tombaugh was already a big-time astronomy star when he arrived as a lowly undergraduate at Kansas University in 1932.

“I felt more attune to the professors than the other students,” Tombaugh said in a later interview. “Of course, I was older than the other freshmen, and I was acquainted with the profession. And I studied very hard.”

Tombaugh was born in 1906 in Illinois and grew up on a farm near Burdett, in western Kansas.

Growing up, he had made sketches of Jupiter and Mars using a 9-inch telescope he made from scratch on the farm. He sent some of the sketches to the Lowell Observatory near Flagstaff, Ariz., which offered him a job.

“He was a very good amateur,” said Steve Shawl, KU professor of astronomy and physics who knew Tombaugh. “He had made a lot of drawings of planets. On the basis of that, they hired him and trained him. He was a very bright guy.”

In 1930, while working at Lowell, Tombaugh made the discovery of his career: a new planet beyond Neptune that later would be called Pluto. He was only 24 at the time.

“You should make a great discovery when you are young,” he told those gathered at KU for a lecture marking the 50th anniversary of the planet’s discovery. “That way you are able to celebrate it on the 50th anniversary.”

Shawl said KU heavily recruited the astronomer.

One report said the $2,000 in private scholarships Tombaugh received during his undergraduate work represented 5 percent of the KU Endowment Association assets at the time.

“He felt he would need a degree to make his mark,” Shawl said.

Tombaugh studied under KU professor Dinsmore Alter, who wouldn’t let the discoverer of Pluto take the university’s introductory astronomy class.

Clyde W. Tombaugh is shown with the William Pitt telescope at Kansas University in this archive newsprint.

“He said it would be unthinkable for the discoverer of a planet to come in and take beginning astronomy,” Tombaugh recalled.

Tombaugh graduated with his bachelor’s degree in 1936 and his master’s in 1939.

He spent the majority of his professional career at New Mexico State University, where he worked from 1955 until 1973. He remained active as a professor emeritus until his death at age 90 in 1997.

Tombaugh’s other discoveries included six star clusters, two comets, hundreds of asteroids, several dozen clusters of galaxies and one super-cluster.

A news release issued by NMSU following Tombaugh’s death noted a phrase Tombaugh liked to use when describing his accomplishments as an astronomer.

The comment: “I’ve really had a tour of the heavens.”