TOMBAUGH CLYDE W.: (1906-1997) American astronomer who discovered Pluto in 1930. Signed colour 10 x 8 photograph, the official NASA image being an artist's conception of the Pluto-Charon binary planet, with the brighter Pluto in the background and the darker surface of Charon in the foreground. With extensive printed facts and information to the verso. Signed by Tombaugh in bold black ink to the upper white border, adding the words Discoverer of the 9th planet, Pluto and date of discovery, 18th February 1930, in his hand. About EX