Clyde Tombaugh Lecture
Discoverer of Pluto

An Idea is Born

Amos Hoff, our founder, passed away in 1987.  Keith Parizek, Treasurer of PAS at that time, suggested a fitting tribute would be an Amos Hoff Memorial Lecture, and this idea was whole-heartedly embraced by the membership. It was proposed to be annual event, hosted jointly by PAS and SAC, both progeny of the POA, but while the lecture never became a "series," the one-time event was a resounding success. 

The Planning Stage

Clyde Tombaugh, discoverer of Pluto, was residing in Las Cruces, New Mexico at this time while working with New Mexico State University (NMSU) in sponsorship of his Tombaugh Scholars Fund.  Parizek suggested Tombaugh would be a speaker of appropriate magnitude for our Memorial Lecture.  In fact, Parizek had actually been in contact with Tombaugh several years earlier regarding construction details for a blink comparator he was building.  He decided to contact him again and invite him to be our premiere speaker.  Tombaugh graciously accepted, and the lecture was scheduled for Friday, March 25th, 1988.  The venue would be the gym at Brophy Prep, then host for our regular meetings in their Physics Lab.  Seating was available for hundreds there, and the publicity effort was driven by both PAS and SAC with the help of local media.

The Tombaughs, Clyde and Patsy, were invited to stay at the Parizek's home in Paradise Valley for the duration of their visit.  This also provided for a personal social event prior to the actual lecture and members of PAS and SAC got to chat informally with the Tombaughs.  It's not every day that one gets the opportunity to visit with the discoverer of a planet, and all were very excited by the prospect.

Discovering Pluto … Again

Prior to the visit, Parizek had scanned images of the Pluto discovery plates and printed them on acetate sized for his now completed blink comparator.  After the Tombaughs arrived, Keith asked Clyde if he recalled the phone conversation about the comparator.  Even though it had taken place many years earlier, Clyde did indeed recall it as "one of the more interesting phone calls he received while at NMSU."  Keith asked him if he'd like to see the apparatus without mentioning that he had surreptitiously installed the copied discovery plates. Keith told him the comparator was set up with some "old plates" related to an asteroid he'd imaged, so Clyde sat down, peered into the eyepieces, and started toggling the images.  He went back and forth between the images a few times, then, slowly, as he recognized what he was seeing, a knowing grin spread across his face.  Clyde stood up, still smiling, and said "Thanks! I just discovered Pluto for the second time."

The Lecture

On Friday, March 25th, hundreds of astronomy enthusiasts from around the valley arrived at Brophy Prep for the evening's lecture.  At 7:45 pm, after a brief introduction by Parizek and Richard Wasson, then PAS President, Tombaugh took the podium and spoke for about two hours on his discovery and career.  His story was accompanied by a 35 mm slide show featuring highlights of his astronomical adventures.  A question and answer period followed.  The evening closed with opportunity to purchase an autographed poster showing a composite of images relating to his Pluto discovery. 

All funds generated by the event benefit the Tombaugh Scholar Fund, established to assist astronomy majors at NMSU.  

An excellent tribute to both Hoff and Tombaugh, this was one of the major events in the history of PAS.