On the Cover: The hard, rocky planets lead violent lives, bombarded from space, riven by tectonic forces, beset by volcanic eruptions, and their faces bear the scars. This is the Memnonia Fossae region on Mars. Here we see impact craters that have been weathered by wind and possibly water, partly filled in by lava from the great Tharsis volcanoes, and then, for the large crater at the top, cracked apart by tectonic forces. By determining the order in which such scars form, scientists piece together the history of a planet. (This image covers an area 206 kilometers, or 128 miles, across.)
4 What is the Value of Space Exploration? Charlene Anderson presents the opinions of a powerful group of thinkers, addressing possibly the most difficult question to answer in our advocacy of planetary exploration.
6 Steps to Mars II: A Conference Report: Louis Friedman presents experts' reports from the second of the Society's Mars exploration conferences.
12 On Target: Galileo Approaches the Jovian System: Charlene Anderson gives a brief guide to the mission to help you get the most from Galileo's anticipated discoveries.
3 Members' Dialogue NASA budget woes; preserving the Moon.
15 World Watch European budget problems and Mir.
16 Basics of Spaceflight Telemetry and command.
18 News & Reviews The dramas of nature acted out in the night sky.
19 Society News Expedition to Belize, involvement in a Mars mission, and Planetfest.
20 Q&A What happens to old spacecraft after they've completed their missions?