"Out from behind the shadow of the earth, we are into the constant sunlight. In a way, there is constant darkness as well, for it depends on which way one looks. Toward the sun, nothing can be seen but its blinding disk, whereas down-sun there is simply a black void. The stars are there, but they cannot be seen because, with sunlight flooding the spacecraft, the pupil of the eye involuntarily contracts, and the light from the stars is too dim to compete with the reflected sunlight, as both enter the eye through the tiny aperture formed by the contracted pupil. No, to see the stars, the pupil must be allowed to relax, to open wide enough to let the starlight form a visible image on the retina, and that can be done only by blocking out the sunlight. In practical terms, that means putting metal plates over all five windows, and then pointing the telescope at exactly the right angle, an angle which is not only away from the sun but which also does not permit any sunlight to bounce off the LM or CM structure into the telescope's field of view. Under these conditions the eye slowly "dark adapts" itself, and the brighter stars gradually emerge from the void. After a few minutes the familiar patterns of the constellations become recognizable (assuming you are fortunate enough to have familiar constellations in the part of the sky you have been forced to use to escape the sunlight), now the navigator can continue with his work."
- Michael Collins, Carrying The Fire
