posted on Jan, 9 2011 @ 08:51 PM
The "hot spots" are the result of the lunar soil's tendency to reflect light back toward its source. There are many reasons for this, but it is
mostly due to countless tiny glass spheres found in the lunar soil, and formed by meteorite impacts. When you see a photo taken "down sun", away
from the Sun, you see what looks like a spotlight around the shadow's head. This is because the light is strongly reflected back toward the Sun, so
the soil around the head of the shadow looks very bright. This phenomenon also explains why the surface fades so drastically toward the horizon. It is
brightest near the foreground due to sunlight being preferentially reflected back toward the camera. Farther away, the sunlight is preferentially
reflected away from the camera, making the ground look dark. This phenomenon can also be observed in wet grass on Earth, as spherical water droplets
act like the glass spheres. The technical term for this phenomenon is Heiligenschein, and is the result of light refraction, reflection, and
diffraction on the surface of and inside the glass spheres and/or water droplets