M 3. The Lunar Environment
   M 3.1. Comparison of Earth and Moon
   M 3.2. Apollo Astronauts' Experience
      M 3.2.1. Working in Lunar Gravity
      M 3.2.2. Working in a Space Suit
      M 3.2.3. Visibility of the Lunar Surface
      M 3.2.4. Estimating Distances
   M 3.3. Lunar Terrain
   M 3.4. Moon Dust
   M 3.5. Temperatures on the Lunar Surface
   M 3.6. Heat Flow
   M 3.7. Seismic Activity
   M 3.8. Polar Environment
   M 3.9. Lunar Atmosphere
   M 3.10. Meteroid Bombardment
   M 3.11. Radiation Environment
   M 3.12. Orbital Mechanics
   M 3.13. Lunar Transient Phenomena
   M 3.14. Mapping the Moon