Top Ten Discoveries of the Mars Exploration Program
1. Ancient, Persistent Liquid Water
2. Complex Surface Geology
3. Modern Water
4. Recent Climate Change
5. Planetary Magnetism
6. Martian Climate and Weather
7. Modern Processes
8. Methane on Mars
9. Gravity and Figure
10. Mars Radiation Environment
Sunset at Gusev Crater Image: NASA/JPL/Texas A&M/Cornell
Credits: Top Ten List: Dave Beaty and Rich Zurek Contents: Susan Gendreau Editor: Charles Budney Web Developer: Kirk Goodall