Ever stopped to wonder why the sky seems to be painted in streaks of color at sunrise and sunset? One day, while driving in the Buena Vista Grasslands along Taft Avenue (just south of Plover Wisconsin) I found the answer; farmers paint the sky in the early evening using pivot irrigation. The paint then gently settles from the sky at night ripening and coloring various crops. During the day, these same systems are used to irrigate crops.
Pivot irrigation systems are a common sight in the Buena Vista Grasslands of central Wisconsin. This area is the former bottom of Glacial Lake Wisconsin formed from meltwater of glaciers that extended to just east and north of Stevens Point some 15,000 years ago. While the lake was being formed, meltwater silt and sand settled to the lake bottom resulting in today’s sandy soil. As sandy soil does not hold moisture, irrigation has become a necessary part of agriculture. Overhead high-pressure irrigation is becoming less common as the industry is converting to more efficient low-pressure sprayers hanging beneath the superstructure.
Glacial Lake Wisconsin was formed because meltwater was prevented from draining down the Wisconsin River due to a huge ice dam at the Baraboo Hills. When the ice dam eventually failed, Glacial Lake Wisconsin drained over several days forming Wisconsin Dells.
Of course, nature also plays an important role in coloring the sky. Unless we are looking directly at the Sun, we only see objects and perceive colors based on the reflecting or scattering of light. If there is no scattering or reflecting of light, we do not see it.
I find it fascinating to contemplate everyone on Earth who sees sunlight at a moment in time, see the same sun beam at virtually the same instant. How we perceive the light is dependent on what types of particles it encounters on the path to our eyes.