WHAT will the end of the world be like ? In the Fels Planetarium of the Franklin Institute at Philadelphia, recently, thousands of persons witnessed a preview of this spectacle, the most gripping that man will ever see. “Canned” sound effects from great electrical storms added realism to the thrilling images of cosmic cataclysms thrown on the planetarium dome by a giant projector to dramatize four possible ways in which life on our planet may be destroyed—by burning, collision, freezing, and explosion. Paintings reproduced in these pages show the tragic scenes they suggest. Sometimes a star becomes a “nova,” or mysteriously flares up in brightness. Suppose that suddenly our own star, the sun, should likewise act as if a vast bellows were blowing a draft into its molten interior. In eight brief minutes the resulting blast of radiant heat would reach the earth, and all life on this planet would vanish in clouds of steam and puffs of smoke. Fortunately, however, the chances of such celestial fireworks are remote. The sun probably was a nova when the solar system was born and is unlikely to repeat the performance.