ASTRONOMERS: A large 4to printed souvenir copy of the treaty entitled Cooperation in Space, being an agreement between the United States of America and the Union of Soviet Socialist Republics concerning cooperation in the exploration of the use of outer space for peaceful purposes, signed in Moscow, 24th May 1972, individually signed by the astronomers Clyde Tombaugh (1906-1997, American Astronomer who discovered Pluto in 1930), James Van Allen (1914-2006, American Space Scientist, discovered the radiation belts named after him in 1958) and Lubos Kohoutek (1935- , Czech Astronomer who discovered minor planets and comets). All have signed in bold blue or black inks to clear areas of the borders and each have also added a brief summary of their most important achievements in their hands. Also featuring a United States postage stamp and First Day of Issue cancellation at Washington DC, 23rd April 1973. A few very minor, light corner creases, otherwise VG