29 January 1930
Discovery of Pluto
Tombaugh exposes the second of the two photographic plates later used to identify Pluto's motion against background stars.
Historical place archive
Browse historical events and people recorded at Flagstaff, Arizona in United States of America. The records below are rendered directly from the World History Database into this page's initial HTML.
Tombaugh exposes the second of the two photographic plates later used to identify Pluto's motion against background stars.
Using a blink comparator, Tombaugh identifies a moving object on plates taken January 23 and January 29, discovering Pluto.
Lowell Observatory director Vesto Slipher announces Pluto as the proposed name for the newly discovered world.
Harrington calculates the expected positions of Pluto's suspected satellite, supporting the conclusion that the observed bulge is an orbiting moon.
New photographs from the U.S. Naval Observatory confirm that the recurring elongation beside Pluto is caused by an orbiting satellite.
The discovery of Pluto's moon is formally announced to astronomers through IAU Circular 3241.
Provenance
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