The moon was still fully lit at 4:05 MT, so I got ready and went out in my backyard a little after 5. I discovered the moon was too low to be seen over the trees, so I packed up to head the office. I went to a good vantage point in the neighborhood and set up my tripod. I caught the last direct rays of sunlight hitting the moon and then it was fully orange – a Blood moon, in the earth’s penumbra (shadow) so only the reddish light spectrum. This shot was one of the last I got because shortly afterward it dropped behind a cloud bank. That is an airplane that crossed below the moon during the ~six second exposure. Below is the explanation why sun & moon rises & sets trend toward the orange spectrum…
Even though sunlight may look white to human eyes, it is actually composed of different colors. These colors are visible through a prism or in a rainbow. Colors towards the red spectrum have longer wavelengths and lower frequencies compared to colors towards the violet spectrum which have shorter wavelengths and higher frequencies.
The next piece of the puzzle of why a totally eclipsed Moon turns red is the Earth's atmosphere. The layer of air surrounding our planet is made up of different gases, water droplets, and dust particles.
When sunlight entering the Earth's atmosphere strikes the particles that are smaller than the light's wavelength, it gets scattered into different directions. Not all colors in the light spectrum, however, are equally scattered. Colors with shorter wavelengths, especially the violet and blue colors, are scattered more strongly, so they are removed from the sunlight before it hits the surface of the Moon during a lunar eclipse. Those with longer wavelengths, like red and orange, pass through the atmosphere. This red-orange light is then bent or refracted around Earth, hitting the surface of the Moon and giving it the reddish-orange glow that total lunar eclipses are famous for.
And this great pic by listener John H: