Clyde Tombaugh autograph note signed on a photocopy of a book review of his 1980 book: ''Out of Darkness: The Planet Pluto''. Note, dated 15 July 1980, is written vertically in the center of the page and reads in part: ''...I can only refer you to my forthcoming book for answers to your questions. The book is illustrated with many pictures from my original planet search...'' Signed ''Clyde W. Tombaugh''. Note measures 8.5'' x 11'' with folds from mailing, else near fine. Includes original postmarked envelope.