Group of three items: an ALS signed "Clyde W. Tombaugh," one page, 8.75 x 5.5, April 15, 1995, in part: "I took the discovery pair of plates in January 1930. I was not able to scan ('blink') them until 18 February, using Earth's daily orbital motion to provide 'parallax.' When I spied a tiny, faint image to shift position…I knew instantly that the object was far beyond the orbit of Neptune—about one thousand million miles beyond!"; a 10.5 x 8.5 sheet headed "Discovery of the Planet Pluto," annotated in blue ballpoint in Tombaugh's hand but bearing a pre-printed signature; and an official color 10 x 8 NASA lithograph of artwork rendering Pluto, signed at the top in black felt tip by Tombaugh. In overall fine condition.
Terms and abbreviations used in our descriptions.