On the Cover:Apollo 15 astronauts photographed the Aristarchus-Prinz region of the Moon from their command module. Crater Aristarchus, about 40 kilometers in diameter, is at upper right. In the foreground are the lava-drowned, ruined ramparts of the ancient crater Prinz and the mysterious network of rilles believed to result from more recent volcanic activity. AS15-2607, courtesy JPL/NASA
4 Going to Mars by Way of the Moon: Michael Duke explains the role of a lunar base in Mars exploration.
8 A Talk With John Aaron: Louis Friedmansits down with the head of NASA's new Office of Exploration to discuss his job, the state of NASA, and the future.
3 Thirty Years of SETI NASA's administrator looks at the search for extraterrestrial intelligence.
12 World Watch Soviet-U.S. cooperation, CRAF, and NASA's space station.
13 News & Reviews Yes, we've been to the Moon before.
14 Society Notes Mars Watch '88, dolphin study, SETI conference, and Astronomy Day.