Have you ever gazed skyward and noticed beams of light shooting out from horizon, or down from the clouds? These columns of sunlit air are called crepuscular rays, or sunrays. They are beautiful, mysterious and very noticeable.
Crepuscular means like twilight or dim. That’s a clue that this effect is often seen around sunrise or sunset, when the sky is somewhat dark. Crepuscular rays may appear to fan across the sky, but the rays are really parallel to each other. They appear to diverge, much as a road that looks narrow in the distance appears wide beneath your feet. Airborne dust, droplets of water and the air molecules themselves are what make the sunrays visible. Next time you see them, remember to turn around. You might be in luck and see fainter and less noticeable anticrepuscular rays.
Bottom line: Beams of light shooting out from horizon, or from the clouds, are called crepuscular rays, or sunrays. These columns of sunlit air are beautiful, mysterious and very noticeable. Photo gallery here.
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