Does the brightness of the moon depend upon the lunar phase? How can you measure the brightness of the moon?

Question

Does the brightness of the moon depend upon the lunar phase? How can you measure the brightness of the moon?

Answer 1

lunar phase would only cause more or less land mass to be exposed-to measure try using a shade chart to compare with-reflection will vary

Answer 2

The brightness of the Moon depends on two things. First the actual phase of the Moon, since that determines how large an area it presents to us. The brightness is also affected by the angle at which the Sun's rays strike the Moon, since the lunar regolith (surface material) behaves somewhat like the glass beads in highway signs, reflecting more light back towards the light source than at any other angle. So at Full Moon, we get a double whammy: 100% of the disk is illuminated, plus the Sun is directly behind us, so there is much stronger reflection directly towards us than at any other phase.

The actual brightness of the Moon is measured with a photoelectric photometer, just like the brightness of any astronomical object. A trick used by lunar eclipse observers is to view the Moon through reversed binoculars, so that its size is more directly comparable to that of comparison stars.