Montana isn't called Big Sky Country for no reason. But just how does our “Big Sky” get its color?
It is common knowledge that our background sky color in the daytime is blue. But why is this? Why do we even see the color blue and not just outer space? Well, this is due to a process called Rayleigh Scattering.
Light is a form of electromagnetic radiation. The sun emits all sorts of radiation, but the electromagnetic radiation we can see is known as visible light, which consists of every color.
As visible light reaches the Earth, it encounters gas molecules in our atmosphere. Since the molecules are smaller than the wavelength of visible light, some of the energy is scattered by the molecule, while the rest is absorbed. Blue light is scattered the most due to its shorter wavelength, so this is the color we see.
The higher up in elevation you are, the less blue the sky will appear to be because there are less air molecules for the visible light to be reflected off.
Sunsets and Sunrises appear redder because light must travel further through our atmosphere to reach the observer as opposed to being directly overhead, so only the longer wavelength colors like red, orange, and yellow are visible.
There are some other, smaller scale atmospheric phenomena that can create some beautiful sky colors like rainbows and auroras
Rainbows are visible when light interacts with water droplets. The light is refracted, or bent, as it passes through raindrops. Since raindrops are circular, the reflection it creates is also circular. But we don’t see the full circle because the ground we stand on gets in the way, so we see a bow shape instead!
Auroras, or northern lights, are caused by charged particles from the sun hitting atoms high up in the earth's thermosphere. The particles follow the Earth’s magnetic field and get funneled into the poles. Once they reach the upper atmosphere, they interact with nitrogen and oxygen molecules to create dazzling light displays in the night sky. The color of the aurora is dependent on the height of the interaction, as well as the type of molecule the particles interact with.
And now, you’re a little more Weather Wise.
