Bad Astronomy: Misconceptions and Misuses Revealed, from ...

168 ARTIFICIAL INTELLIGENCE
sunlight from the air to fill them in. Without any light illuminating
the ground in the shadow, it should be completely, utterly black.
On the Earth, we are accustomed to shadows that are not actually
totally black. This is due primarily to our bright sky. The Sun
itself casts a sharp shadow, but the light from the air in the sky
illuminates the ground in our shadow, making us able to see objects
there.
On the Moon, where the sky is black, conspiracy theorists claim
the lunar surface inside the shadow should be completely black. If
the Sun is the only source of light, they say, the shadows should be
black as pitch. Yet, in the astronaut photographs we commonly see
shadows filled in a bit, as if there were another source of light.
Obviously, to the hoax-proponents, since the Apollo photographs
were taken on a soundstage on Earth, the source of this light is the
air inside the building, scattering the light from a spotlight.
However (stop me if you’ve heard this before), they’re wrong.
There is a source of light on the Moon besides the Sun, and we’ve
already said what it is: the Moon. The sky may be black, but the
surface of the Moon is very bright and reflects the sunlight, filling
in the shadows. This is another trivially simple answer to one of
the hoax-proponents’ “puzzling” questions.
Interestingly, sometimes the shadows falling on the lunar surface
appear to be filled in as well. Ironically, the source of light is
most likely the astronauts themselves. The spacesuits and the LM
are brightly lit by the Sun and the lunar surface, and that light is
reflected back onto the lunar surface, filling in the shadows a bit.
This exact same technique is used by photographers and cameramen,
who employ umbrella-like reflectors to fill in the shadows
when photographing a scene.
However, if you look more closely at the photographs, the
problem does get more complicated. In what has become the most
famous picture taken on the Moon, Neil Armstrong snapped an
image of Buzz Aldrin standing near the LM during the Apollo 11
mission (see page 169). We see Buzz facing the camera, lit by the
Sun from behind and to the right. Reflected in his helmet we can
see Neil’s image as well as the lander leg and various shadows.