Challenge of the universe / by J.Allen Hynek ,Student activities by Norman D. Anderson. Illustrated by Helmut Wimmer. Advisory group: research scientist, Nancy G. Roman; science educator, John S. Richardson; science teacher, Norman D. Anderson. Hynek, Joseph Allen, 1910- Astronomy. QB44 .H9 523.01 HYC Includes bibliography. New York : Scholastic Book Services. c1962 c1962 1962 Text 143 p. : eng Vistas of science, 4