These
star trails were photographed in south Texas at 30 degrees north latitude.
Orion is in the center, as in the previous image. Latitude explains why these
trails are slanted. Near the equator, in East Africa, stars in the eastern
sky trail directly up and over your head. At higher latitudes, as here, you
are tilted with respect to the rotating "sphere" of the sky. At
either pole the stars would go around the horizon. This sky is blue, photographed
with the same lens as the previous image and on the same emulsion (Provia
100), processed by the same photo lab.
