On the Cover: The Genesis Rock was one of the great prizes returned to Earth by project Apollo. 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. Graham Ryder, Lunar and Planetary Science Institute
4 The Gift of Apollo: Carl Sagan looks back on the achievements of Apollo with this essay concerning the moment and the meaning of those first steps on the Moon.
6 While We Weren't Watching: Apollo's Scientific Exploration of the Moon: Andrew Chaikinreminds 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 Spencershares 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 Andersonpresents 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?
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