In a message dated 98-10-15 22:44:51 EDT, you write: << If full moon is -12.8, it needs rm = -24.9, which gives an albedo of 0.25! Half moon would be -12.0, and one day moon (ph=12 d) -7.8. Something does not quite right there. >> The moon is covered with fine dust, which strongly reflects back toward the light source instead of scattering light in all directions. As a result, the full moon is 12 times brighter than the half moon. Jim Mason