4 entries match your criteria.
Related Historical Markers
New Mexico State University Library, Archives and Special Collections
Marker detail: Clyde Tombaugh at the Lowell Observatory
one year after discovering Pluto.
one year after discovering Pluto.
SHOWN IN SOURCE-SPECIFIED ORDER
1 ► Illinois, LaSalle County, Streator — Streator's Stargazer —  |
| 2 ► Illinois, LaSalle County, Streator — Clyde William Tombaugh — |
| 3 ► Kansas, Pawnee County, Burdett — 109 — Discoverer of Pluto — |
| 4 ► Arizona, Coconino County, Flagstaff — Lowell Observatory — National Historic Landmark — |