On the Cover: With each passing glance, Mars continues to surprise and delight. These dark, wild streaks are the trails of dust devils that run over hills, skim straight across dunes and ripples, and dance through fields of house-sized boulders. The Mars Orbiter Camera on Mars Global Surveyor imaged this 3-by-5 kilometer (2-by-3 mile) portion of Argyre Planitia on February 21, 2000. MSSS / NASA
4 Contamination From Mars: No Threat: Robert Zubrinexpresses his views on planetary protection when it comes to protecting Mars and Earth.
6 What Might Have Been: The Mars Polar Lander and Mars Climate Orbiter Losses: Andre Bormanisprovides a summary of the reports from expert panels on what went wrong and how to fix it.
10 Mars Global Surveyor: Performing Daily, 687 Days a Year: Jennifer Vaughn reminds us about this mission, still dutifully collecting data in orbit of the Red Planet.
18 Human Exploration of Space: Fact and Fantasy:Charlene Anderson gives a brief preview of a new NPR special coming out this summer.
3 Members' Dialogue SETI; tracking NEOs.
17 World Watch Private spaceflight projects.
20 Q&A Could Europa's ocean be too salty to support life?
22 Society News LEGO donates Red Rover, Red Rover Systems.