If Moonlight is just the Sun’s light reflecting off the moon, and when Sunlight passes through the atmosphere it turns yellow, why does the daytime Moon look white?

1.13K views

I know that in space the Sun looks white, but still.

In: Physics

3 Answers

Anonymous 0 Comments

Both the Sun and Moon are affected by Rayleigh scattering, which causes blue light to scatter away, leaving them appearing yellowish. The effect is stronger when either body is low to the horizon, and weak when they are high in the sky.

During the day, the blue light scattered from the Sun can mix in front of light from the Moon, causing the Moon to appear more white, though with blue “shadows”. The Moon appears most yellow when it is near the horizon, and the Sun is also low or below the horizon.

Anonymous 0 Comments

In daytime sun also look white, its only in evening and morning sun look orange or reddish, because red light has highest wavelength in visible range so it scatters less. With enough scattering, almost all of the shorter wavelengths can be removed from the original beam of sunlight. This turns the unscattered light orange or red

Anonymous 0 Comments

In the day the Sun is by far the most powerful light source, which causes the sky to glow blue with Rayleigh scattering.

That overwhelms any possible colour cast you’d get off the moon.

In any case, the orange effect you get from the Sun is most prevalent when the Sun is low in the sky (sunrise or sunset), and it has a thicker section of atmosphere to go through. That scatters all the blue away so you’re left with red.

The same thing happens with the Moon when it’s low in the sky, for the same reasons, [see this photograph](https://www.almanac.com/sites/default/files/styles/primary_image_in_article/public/image_nodes/low-moon.jpg?itok=3OoAGm7U)