Fig. 1 - The shadow indicated (a) appears significantly longer than
the other astronaut's shadow. (NASA: 16mm DAC frame from
Fig. 1(a), casts a significantly longer shadow than the other. This
could happen if they were being lit by different light sources. Since
the sun is the only significant source of light on the lunar surface,
their shadows should be equally long. [Mary Bennett David
We can reject the multiple light source theory without too much
difficulty. Notice that the astronauts are closely in line with each other
with respect to the light source. A light set to illuminate one could
hardly avoid also illuminating the other. This would cause each
astronaut to cast two shadows, one from each light source.
Many of Bennett's and Percy's arguments are based on apparent
lengths and directions of shadows cast in photographs. Their argument
in this case and many others presumes a flat level surface upon which
to cast shadows. The foreground of the image is darker than the
background, indicating that the terrain is not at all level. The
ground slopes downhill away from the camera to roughly the center of
the image, then begins to slope upward again and receives more direct
With 3D graphics we can see the behavior of objects casting shadows
onto variously sloping surfaces. In Fig. 2 the two cylinders are
exactly the same height, but are on different sides of a shallow
depression. The light source shines at a low angle from a great
Fig. 2 - Computer-generated images of objects of
identical height casting shadows of different length on an
The view in Fig. 2 (right) is from directly overhead and shows
clearly that the shadow cast by the cylinder on the "downhill" side is
distinctly longer than the other shadow. Note also that the ground
exhibits exactly the same kind of variable lighting that we see in the
photograph, helping confirm that this (not some mysterious extra light
source) is the phenomenon at work, although we note that the variation
might also be caused by the astronauts churning up darker subsurface
Fig. 3 -A crude apparatus to demonstrate the
theoretical principle in Fig. 2, seen here edge-on to show
Fig. 4 -The apparatus in Fig. 3 seen from
approximately the same angle as the astronauts photographed from the
LM in Fig. 1.
Figs. 3-5 show a crude apparatus to test the basic optical principles
described above and shown synthetically in Fig. 2. The pasteboard
sheet is bent to simulate a fluctuation in terrain. This fluctuation
is exaggerated compared to what is likely the case near the flag pole
at the Apollo 11 landing site. In Fig. 3 the apparatus is seen
edge-on to show its curvature and the lengths of the dowel pins.
Fig. 5 -The apparatus in Fig. 3 seen from overhead.
It is propped up to simulate a sun elevation of approximately
10° at a time of day where the sun elevation was some 60°.
In Fig. 4 the line of sight is approximately that of Fig. 1. It
can be clearly seen that the shadows are of different lengths. The
dowel pin nearest the sun casts a lengthier shadow, just as the up-sun
astronaut in Fig. 1 casts a lengthier shadow.
Fig. 5 is the same setup as seen from "above" -- i.e., from what
would be overhead were this arranged horizontally. Here all trace of
shadow distortion due to curvature vanishes, and the difference in
shadow length is most apparent.
Other frames from the
same film show the astronauts casting shadows of equal length as they
move about. They are obviously moving toward and away from a large
light source. [Mary Bennett and David Percy]
Again Bennett and Percy rely heavily on their presumption that the
ground is essentially flat. The shadow of someone walking around on
rough terrain would also lengthen or shorten. A low sun elevation
would greatly amplify such differences in shadow length.
Fig. 6 - The Apollo 11 astronauts standing
apart from each other. (NASA: Apollo 11 16mm DAC still
In this case, we consider that the astronaut on the right in
Fig. 1 is standing atop a small rise and the astronaut on the left is
at a lower elevation, casting his shadow on mostly level ground.
We further consider that one astronaut in Fig. 6 has stepped back
away from the flag while the other one has gone some distance away,
probably to take photographs. He is no longer on the small rise and
is now also casting a shadow onto relatively level ground.
Bennett's and Percy's argument that the shadow lengths are caused
by variations in illumination angles due to a nearby (versus
infinitely distant) light source would also require the shadows to
diverge slightly in the second photograph. But we observe the shadows
to be virtually parallel, converging slightly due to the perspective
we would expect from such a camera angle. But if Bennett and Percy
are correct, the distant astronaut's shadow should point farther away;
the shadows should appear to diverge.
Fig. 7 shows what would happen if David Percy's hypothesis were
attempted. The astronaut closer to the light would cast a short
shadow compared to the one cast by the one farther away from the
light. But in Fig. 1 the astronaut closer to the hypothetical
light is casting the longer shadow. Clearly this cannot be
caused by the divergence characteristic to a nearby light.
Fig. 7 - Astronauts illuminated by a nearby light.
The astronaut farthest from the light will cast the longer
shadow, and the shadows will diverge slightly if the
astronauts are laterally displaced from the axis of
Fig. 8 - Two cylindrical power-tool batteries
illuminated by a 75-watt PAR 32 studio lamp from a distance
of 18 inches (0.5 meter).
Fig. 9 - The same objects as in Fig. 8, placed the
same distance from the light but displaced perpendicular to
the lighting axis. Note the extreme divergence of the
Figs. 8 and 9 demonstrate this empirically. Fig. 8 shows that the
length of the shadow of the closer object is shorter. It also shows
that the shadows diverge in distance. However this effect will be
mitigated in a more realistic lighting design.
Fig. 10 - The same objects as in Fig. 9 illuminated
In Fig. 9 the objects are a similar distance from the light, but
are separated laterally as theorized by Bennett and Percy to explain
Fig. 6. However we can see that the shadows will appear to diverge,
whereas in Fig. 6 the shadows appear to converge slightly.
In Fig. 10 the same objects are illuminated by sunlight. They
appear very nearly parallel, but actually converge slightly as perspective dictates. Clearly the objects
illuminated in sunlight produce shadows closer to those in Fig. 6 than
objects illuminated with artificial studio lighting.
Photos of the area show
it to be flat. [Mary Bennett and David Percy]
The authors present the photograph in Fig. 11. Their argument appears
to be, "It's flat because it looks flat to us." The horizon isn't
flat, but that's anywhere from a hundred feet to five miles away from
the area we're interested in.
Fig. 11 - A photograph of the area in the film footage
as reproduced on Aulis Publishing's web site, ostensibly to
prove that the terrain is flat. (NASA: AS11-40-5905)
The question to ask is whether we'd see any evidence variation if
it really were there. What would be sufficient evidence of terrain
variation? We might expect to see variations in the lighting.
Terrain less directly lit might appear darker, as we noted above. We
might also look for hard-edged discontinuities that represent the
crests of rises. We might also look for objects that disappear
abruptly as if behind rises. We might also look for shadows that
behave a bit differently than expected.
Observing some or all of these would suggest a variation in
terrain. But would failing to observe them prove that the
terrain was flat? No. In logic this is called the fallacy of inverse
implication, encapsulated by the maxim, "Absence of evidence is not
evidence of absence." Just because Bennett and Percy fail to observe
any expected indicators of slope doesn't mean no such slope exists.
There are cases in which the slope exists without exhibiting the most
For this specific photo, we note little color variation, no
hard-edged discontinuities. It's unclear whether the flag pole
disappears behind a rise or simply into the soil.
The shadow in the foreground is cast by the solar wind collector. As
shown in Fig. 12, the collector is simply a rectangular sheet of
material hung on a pole to collect particles from the solar wind. The
shadow shows it was correctly deployed facing the sun as directly as
Fig. 12 - The solar wind experiment. Its top is
square and it is oriented facing the sun. (NASA: AS11-40-5873)
Correctly aligned, the square top should cast a nearly-perfect
rectangular shadow. But in the authors' proof photo we see the tip of
the collector's shadow become gradually thinner, as if it were falling
on a patch of ground sloping away from the camera.
The strongest evidence, however, of irregular terrain is the
shadow of the flag and flagpole. They are mostly invisible in Fig. 11
(the authors' version of the photo), but we can examine it more
closely in a larger image (Fig. 13).
The white line represents a theoretical straight line that would be
the shadow cast by a perfectly straight flagpole. But it is plain
that the shadow is not perfectly straight. Since Bennett and Percy
cannot argue that the object casting the shadow is curved, nor can
this effect be produced by artificial light sources, we have no choice
but to conclude that the surface onto which this shadow is being cast
is not planar.
Fig. 13 - An enlargement of the flagpole shadow area
of Fig. 11. The periodic white line represents the
theoretical straight line. The shadow itself is not
straight, indicating a variation in terrain. (NASA:
AS11-40-5873, annotation by Clavius)
The evidence Bennett and Percy present to establish a planar
surface is ironically the best evidence of a non-planar
surface. A significant and abrupt change in the angle of the lunar
surface can be found in the area onto which the shadows in question
are being cast. In fact, the flagpole shadow very closely resembles
the simplified computer model in Fig. 2 and the empirical model in
Fig. 4. When viewed from a high angle (Fig. 1) shadows cast onto
non-planar terrain vary in length, but not necessarily in shape.
Linear objects cast apparently linear shadows. But when viewed from a
low angle (Fig. 13), such shadows display a change in shape or
direction, such as we see in the proof photo. Linear objects cannot
cast curved or bent shadows onto a planar surface.
The irregularity in the terrain corresponds exactly to the
location in which the variations in shadow length are observed. We
further note that the flagpole shadow cannot be produced by any of the
hoax methods Percy has suggested, and in fact can only be
produced by a lunar surface irregularity. This obvious irregularity
has the shape and orientation that would produce the shadows observed
in Fig. 1.