On the Cover: The Genesis Rock was one of the great prizes returned to Earth by project <i>Apollo</i>. Here we show a magnified view of individual crystals within the rock. Analysis of this piece of anorthosite fixed its age at about 4.4 billion years—a rare find in a solar system on 4.6 billion years old. Scientists infer that the Genesis Rock formed from the original magma ocean that once covered the surface of the forming Moon.
6 While We Weren't Watching: Apollo's Scientific Exploration of the Moon: Andrew Chaikin reminds us of the contributions Apollo made to our understanding of the universe.
10 Observing a Catclysym: The Last Days of Comet Shoemaker-Levy 9: John Spencer shares the latest developments of this comet on a collision course with Jupiter.
14 The Comet is Coming: The Planetary Society Revs Up for Jupiter Watch: Charlene Anderson presents what the Society has planned for the upcoming collision!
3 Members' Dialogue A broader scope?
16 News & Reviews What killed off the dinosaurs?
18 Readers' Service Could you eat a comet?
19 Society News More tours, conferences, and a contest.
20 Q&A Why hasn't Mars fallen on its side?