The first thing every conspiracist notices about photography in space is that there are no stars in any of the pictures. The general public brought up on science fiction motion pictures is used to seeing stars in pictures purporting to be taken in outer space. And so the real photos seem strange.

The first question I put to the conspiracists is that if NASA wished to perpetuate a convincing fraud, why didn't they produce photos (with stars) that satisfied the public's expectations and didn't raise questions? I get this answer:

Nasa knew they couldn't duplicate the complex arrangement of stars accurately enough to fool people, so they just left them out.

When I was volunteering at the planetarium at Kansas State University we had no problem creating highly accurate starfields. Star maps and planetarium technology were old hat at the time of the Apollo missions. No special expertise required.

So given that they could have, why didn't they?

It's satisfying to discover that the conspiracists' expectations are naive and that the empty black void is just what you would expect to see under those circumstances.

On earth we see the stars in the sky because there is little other light. I live in mountainous country, and if you go up into the mountains where the air is thin and there are no distracting lights, the stars are quite magnificent. But when I return to the brightly lit city and look at the same night sky, I see only the brightest stars. If I go inside the house and turn on all the lights and look out the window, I can't see any stars.

Why not?

Because the iris in my eyes has adjusted to the amount of light. In the pitch blackness of the mountains they're open just as wide as they can be, allowing more light to enter. In the night city, they close somewhat to adjust for the street lights. And inside my house, they are as closed as they are during the daytime in sunlight. A camera's aperture works the same way. To set the exposure for bright exposure means that subtle lights like stars simply won't show up.

Because the sky on the moon is black, we tend to believe the viewing conditions are the same as night on earth. Not true. The sun shines just as brightly (brighter, in fact) on the lunar surface, and so the astronauts' eyes (and camera apertures) were set for photographing in daylight conditions. Neil Armstrong reported not seeing any stars from the lunar surface, except through the navigation scopes (where the eyepiece screened out the other lights).

One conspiracist even goes so far as to claim that the Challenger was intentionally destroyed because civilian Christa McAuliffe would have revealed that stars were indeed visible from space. Sometimes they are, sometimes they're not. With the shuttle's cabin lights on and cameras set to expose for sunlit conditions, the stars are not visible. When the shuttle crosses over into the shadow and you turn all the cabin lights off and let your eyes adjust to the darkness, you see a glorious display of stars. And the shuttle astronauts -- civilian or otherwise -- are quite happy telling everyone this.