Bad:
The next evidence also involves pictures. In all the pictures taken by the
astronauts, the shadows are not black. Objects in shadow can be seen,
sometimes fairly clearly, including a plaque on the side of the lander
that can be read easily. If the Sun is the only source of light on the
Moon, the HBs say, and there is no air to scatter that light, shadows should
be utterly black.
Good:
This is one of my favorite HB claims. They give you the answer in the
claim itself: "...if the Sun is the only source of light..."
It isn't. Initially, I thought the Earth was bright enough to
fill in the shadows, but subsequently realized that cannot be the case.
The Earth is a fraction of the brightness of the Sun, not nearly
enough to fill in the shadows. So then what is that other light source?
The answer is: The Moon itself. Surprise! The lunar
dust has a peculiar property: it
tends to reflect light back in the direction from where it came. So if you
were to stand on the Moon and shine a flashlight at the surface, you
would see a very bright spot where the light hits the ground, but, oddly,
someone standing a bit to the side would hardly see it at all. The light
is preferentially reflected back toward the flashlight (and therefore you),
and not the person on the side.
Now think about the sunlight. Let's say the sun is off to the right in a
picture. It is illuminating the right side of the lander, and the left is
in shadow. However, the sunlight falling beyond the lander on the left is being
reflected back toward the Sun. That light hits the surface and reflects
to the right and up, directly onto the shadowed part of the lander.
In other words, the lunar surface is so bright that it easily lights
up the shadows of vertical surfaces.
This effect is called heiligenschein (the German word for halo). You
can find some neat images of it at
here, for example. This also explains another HB claim,
that many times the astronauts appear to be standing in a spotlight. This
is a natural effect of heiligenschein. You can reproduce this effect
yourself; wet grass on a cool morning will do it. Face away from the Sun
and look at t