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

APPALLED AT APOLLO 169
One of the most famous photographs
from the Apollo missions,
the “Man on the Moon” picture
of Buzz Aldrin. Conspiracy theorists
point to many clues that
indicate the image was faked: the
lack of stars, the filled-in shadows,
and the apparent spotlight
effect. However, all of this is in
fact evidence that the picture is
genuine. Note also Aldrin’s knees;
they are covered with ash-gray
lunar surface powder from the
many times Buzz had to dip down
to pick up a dropped tool or collect
a rock sample. Despite what
others might say, this image was
indeed taken on the surface of an
alien body, the Earth’s Moon.
(Photograph courtesy of NASA.)
This image is of paramount importance to the hoax-believers.
It embodies two claims critical to their arguments: From the way
the ground is illuminated Aldrin is clearly being lit by a spotlight
aimed directly at him, and from shadows in his visor it looks as if
that spotlight is nearby.
This picture is oddly lighted, but not because of any human
trickery. Actually, the spot of light results from a peculiar property
of the lunar surface: it tends to reflect light back in the direction
from which it comes. This is called backscatter, and it is very strong
on the Moon. If you were to shine a flashlight in front of you
there, you’d see the light strongly reflected back to you. However,
someone standing off to the side would see hardly any reflected
light at all.
Actually, you’ve almost certainly seen this effect on your own.
You might guess that the half-full Moon is half as bright as the full
Moon, but that’s not correct. The full Moon is roughly ten times as
bright (H. N. Russell, “On the albedo of planets and their satellites,”