Why do the sun and moon change colors at different times?

This effect is caused by the passage of the sunlight through the atmosphere. Because we live on a (rough) sphere, and the atmosphere is another sphere above that, when the sun or moon is at the horizon the light from it has to pass through about twice as much air as it does when it’s straight up. The molecules in the air naturally “scatter” blue light, which is why the sky is blue. The more air that the light passes through, the more blue light is scattered off to the side. What’s left is the light at more red wavelengths, causing the sun or moon to look red or orange at sunrise and sunset.

The other reason for variation in color depends on what else, besides air, is in the atmosphere. Dust, smoke, and pollution all change the light-scattering properties of air, usually obstructing more blue light and making the sun or moon look even more red. Light pollution can also cause a change in the apparent color of the sun and moon.

In brief, the sun and moon aren’t actually changing colors, but from where you’re standing, not all the light is reaching you, causing the apparent color change. It’s not an optical illusion, but it’s not an actual physical change ocuring on the surface of the sun or moon.

(The moon appearing especially large when it’s near the horizon, has, however been proven to be an optical illusion caused by our brains “expecting” things near ground level to be bigger than things in the sky)

A picture says more than a thousand words sorry @hannahsugs :P Great answer btw!

Because God likes to paint

@hannahsugs
Lurve for a fascinating answer.

@hannahshug ; thank you! ^^

Nothing cooler than a big orange Harvest Moon.

The moon’s color changes based on changes that occur in the Earth’s atmosphere. Above the atmosphere, in space, the environment is very clear, with few dust particles, little time-space distortion and nothing to get in the way of light traveling from the sun to the moon——and from the moon to the earth, as a percentage of the light is reflected on the moon’s surface. Up to a certain point, this light remains undistorted, and we see the best example of this when the moon is directly above the earth and shining with its famous pale-light color.

However, when this light hits the atmosphere, it starts to be disrupted by several different effects, including water vapor, dust particles and angles of view. When the moon is high in the sky, its reflected light passes through a minimal number of these disturbances and the moon appears in various shades of white. However, at different angles and low in sky, the light has to pass through many more of these disruptive factors, which can change both the apparent shape and color of the moon.
In principle, this effect is very similar to the way sunlight changes as it enters our atmosphere. Direct light from the sun is a very bright white or yellow because it passes through the smallest amount of particles and reaches the earth most clearly. Scattered sunlight passes through more particles and turns the sky blue, while the sun at dawn and dusk is level with the horizon and has to pass through a large portion of the atmosphere to be seen by the human eye, changing the color to various shades of red and orange.

All these changes are due to the properties of light and the way it is refracted. Pure light from the sun and moon is made of a wide spectrum of visible light waves, many different colors combined to look white or yellow-white. As this wide-spectrum light hits particles of dust, it bounces off of them, but some spectrum shades are absorbed by the particle, leaving a “smaller” light wave with fewer combined colors to continue traveling through the air. When the light hits a particle of water vapor, it passes through but is refracted off the water molecules, some colors splitting off and traveling in different directions with other colors, generally those with the longest wavelengths, continuing onward. The more atmosphere the light has to travel through, the more particles it runs into and the more often this refraction occurs.

In the end, the light that has the longest wavelengths and has the easiest time traveling straight tends to arrive and be absorbed by the viewer’s eyes. In the light produced by the sun, the blue, red and orange light waves are the longest in the available spectrum and tend to travel the farthest. When the moon is close to the horizon or has to pass through a lot of dust, these are the light waves that make it through to be seen, making the moon appear to be reddish or orange in color. Since blue also has a long wavelength, sometimes the moon, like the sky itself, appears blue, this being the primary color of light to reach our eyes on certain occasions.

The term “harvest moon” is used to described a large red or orange moon, and this phenomenon is generally associated with harvest season, for good reason. In harvest seasons, farmers throw large quantities of dust up into the sky as they plant and till the land. This dust causes the light to refract more easily than usual, both magnifying the moon and allowing only the red-orange light waves to filter through to viewers.