Ti ringrazio per il materiale audiovisivo. Secondo me però l'effetto di luce è dovuto all'effetto Heiligenschein (Aureola del Santo).

It is created when the surface on which the shadow falls has special optical characteristics. Dewy grass is known to exhibit these characteristics, and create a Heiligenschein. Nearly spherical dew droplets act as lenses to focus the light on the surface beneath them. Some of this light 'backscatters' in the direction of the sunlight as it passes back through the dew droplet. This makes the antisolar point appear the brightest.

The opposition effect (also opposition spike, or opposition surge) is the brightening of a rough surface, or an object with many particles, when illuminated from directly behind the observer

As the Mars Exploration Rover 'Opportunity' descended towards Meridiani Planum on Jan 24, 2004 its parachute cast a shadow on the arid Martian surface.

The large image (PIA05146) was taken from an altitude of only 1400m and shows an area about 1.2km (3/4 mile) across.

[omiss]

This image is possibly the first showing an "Atmospheric Optics" effect on another planet