and
threaten man's existence_

DANGER: DINOSAURS! by Richard Marsten--_A treacherous big-game hunter
leads an expedition back to the Age of Reptiles_

EARTHBOUND by Milton Lesser--_An ex-space cadet is forced to plunder
ships he was trained to protect_

FIVE AGAINST VENUS by Philip Latham--_A Moon-bound rocket crashes in the
misty wilds of Venus_

ISLANDS IN THE SKY by Arthur C. Clarke--_A teen-ager's adventures aboard
a space station_

LOST PLANET, THE by Paul Dallas--_Two worlds on the verge of war_

MAROONED ON MARS by Lester del Rey--_A teen-ager on the first
Moon-to-Mars expedition_

MISSING MEN OF SATURN by Philip Latham--_A space crew is held prisoner
by froglike men on Saturn_

MISSION TO THE MOON by Lester del Rey--_Scientists make man's first
journey to the Moon_

MISTS OF DAWN by Chad Oliver--_A space-time machine hurls a 20th-century
boy back to 50,000 B. C._

MYSTERIOUS PLANT, THE by Kenneth Wright--_A young captive on Planet X
prevents Earth's destruction_

MYSTERY OF THE THIRD MINE by R.W. Lowndes--_Prospecting in the dangerous
asteroid belt_

PLANET OF LIGHT by Raymond F. Jones--_A trip to another planet shows how
the universe can be saved from destruction_

ROCKET JOCKEY by Philip St. John--_A space pilot battles Martians in
rocket race_

ROCKET TO LUNA by Richard Marsten--_A stowaway on a Moon-bound rocket
proves his worth_

ROCKETS TO NOWHERE by Philip St. John--_Scientists establish a colony on
the Moon_

SECRET OF THE NINTH PLANET, THE by Donald A. Wollheim--_A high-school
senior investigates the theft of the solar system's light_

SECRET OF SATURN'S RINGS, THE by Donald A. Wollheim--_A scientist proves
his theories by means of a unique invention_

SECRET OF THE MARTIAN MOONS, THE by Donald A. Wollheim--_Scientists
discover the secrets of Martian civilization_

SON OF THE STARS by Raymond F. Jones--_An interplanetary friendship
brings Earth to the brink of destruction_

SONS OF THE OCEAN DEEPS by Bryce Walton--_Undersea terrors nearly thwart
a project aimed at saving a continent_

STAR CONQUERORS, THE by Ben Bova--_The Terran Confederation battles for
its existence against the all-powerful rulers of the Milky Way Galaxy_

STAR SEEKERS, THE by Milton Lesser--_A tale of a spaceship doomed to
crash_

STEP TO THE STARS by Lester del Rey--_The U. S. builds a space
station_

TROUBLE ON TITAN by Alan E. Nourse--_A rocket experimenter discovers a
plot threatening Earth's