On the Cover: Subtle blue-tray clouds hover over the dusty rose Martian surface near Valles Marineris, a series of interconnected east-west canyons spanning roughly 4,000 kilometers (2,500 miles). This is the first color image from the Mars Orbiter Camera aboard Mars Global Surveyor, taken last October 3 about 11 minutes after the spacecraft passed close to the planet for the thirteenth time. It was during these initial passes within the Martian atmosphere that Mars Global Surveyor team members noticed slight movement in an unlatched solar panel, causing mission officials to change the pace of aerobraking, and delaying the mapping portion of the mission one year. Courtesy of Malin Space Science Systems and JPL / NASA
4 The Sun Sets on Mars Pathfinder: Jennifer Vaughn celebrates the new trail to the planets blazed by this true pathfinder.
6 The Shiva Hypothesis: Impacts, Mass Extinctions, and the Galaxy: Biologist Michael Rampinocombines discoveries from astronomy, planetary science, paleontology, and geology to piece together a possible story of what has driven changes in life on Earth.
12 Ice, Water, and Fire: The Galileo Europa Mission: Leslie Lowes talks about Galileo's next mission, zeroing in on Europa's ice, Jupiter's water, and Io's fire.
3 Members' Dialogue Going metric, getting into schools, and humans in space.
16 Basics of Spaceflight Where are they now?
18 News & Reviews Hot rocks; Mars mania.
19 World Watch Multiple mission updates.
20 Q&A What forms a comet's tail?
22 Society News NASA takes on the Mars balloon.
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