Heiligenschein

CONT: It is most apparent when the sun is low in the sky and when the surface is dew-covered. The explanation of the heiligenschein varies depending upon whether it is seen over a dry or a dew-covered surface. When an observer's shadow is cast on a dry, irregular surface (such as gravel or vegetation), each irregularity near the antisolar point covers its own shadow. In other directions, the average brightness results from a mixture of sunlit and shaded surfaces. The lower the sun in the sky, the longer the shadows and so the greater the contrast with the brighter region near the antisolar point.
OBS: The heiligenschein is occasionally called Cellini's halo, after Benvenuto Cellini who described its behavior in his memoirs of 1562. He even pointed out that it appears to the greatest advantage when the grass is moist with dew, but felt its appearance bespoke the wondrous ways of Gods providence toward me. Shades of this interpretation are also found in the name heiligenschein: It is German for the light of the holy one.