Membership Meeting - Before Pluto was Pluto: An Accidental Capture
Sat, Sep 13
|Morris County Library
At Yerkes Observatory, located at Williams Bay, Wisconsin, members of the Asteroid Search and Studies by Amateurs at Yerkes Group (ASSAY), a function of Yerkes’ Outreach Program, found Pluto on 1909 photographic plates while Pluto was discovered by Clyde Tombaugh in 1930.


Time & Location
Sep 13, 2025, 11:30 AM – 1:00 PM
Morris County Library, 30 E Hanover Ave, Whippany, NJ 07981, USA
Guests
About the event


At Yerkes Observatory, located at Williams Bay, Wisconsin, members of the Asteroid Search and Studies by Amateurs at Yerkes Group (ASSAY), a function of Yerkes’ Outreach Program, found Pluto on 1909 photographic plates while Pluto was discovered by Clyde Tombaugh in 1930. Dr. DiMario will present the process of discovery, the significance of the discovery, and present a brief history of Yerkes Observatory and its rebirth.
Dr Michael DiMario has recently retired from Lockheed Martin serving various executive roles and has held executive engineering positions at General Electric Medical and Lucent Bell Laboratories. In regard to his astronomical pursuits, he chairs the Amateur Astronomers Association of Princeton Astroimaging Group, spends many a night astro imaging, and does considerable astronomical history research. He co-shares the earliest pre-discovery of Pluto on photographic glass plates located at Yerkes Observatory.
