# What color is earthshine?

What color is earthshine (e.g the average color of earth that shines on the moon)? I am making a solar system exploration game, and would like to know this for the lighting of my moon level at night, with a "full earth".

Edit: Here is a video including the moon level, bathed in earthshine as the specified color in the answer at "night time" (clip is 12 seconds into the video): https://www.youtube.com/watch?v=HKGCtkps8gk&list=PL9Bk1v7iJfdCpRaQ6vTGYOM-lXAO7RAQ1&index=1

If interested in my game I am making, here is a link to it: https://jonathanlcopeland.wixsite.com/planetary

• Given earth's larger diameter and higher albedo I calculate that a full earth as seen from the moon is about 34 times as bright as the full moon we see. See The Dark Side Of The Moon Jul 27, 2017 at 15:10

In my answer to Color of planets I estimated the colour of the Earth as #2f6a69 (based on averaging the colour in various images of Earth, and adjusting for albedo), but noted that it is the hardest of the planets to give a single colour to.

If you were on the near side of the moon with no sun the cones in your eyes would not be fully active: you would be have Mesopic vision. Also your eyes would adapt to the blue light conditions. As a result you probably wouldn't notice blueness of the light much.

• Thank you! I couldn't quite get it right trying to do it "by eye", it looks much better now! Jul 4, 2016 at 17:36
• By the way, this turns out to be a shade of turquoise, and looks beautiful (as well as probably accurate)! Jul 14, 2016 at 23:37
• are you sure it's that green? true color images i found gave landmass as being more sand color than green, plants are fairly dark compared to quartz. check on a histogram? May 1, 2017 at 19:40
• No, it's not in any sense a rigorous value of the colour of Earthshine. I took some images of the Earth and averaged the hue, then adjusted for the overall albedo. It's meant as a first approximation. The colour of the Earth is quite variable. It rotates so sometimes land masses face you, and sometimes oceans. Sometimes there are more green plants, sometimes there is more snow or cloud. However, this is my best attempt at a single value for the colour of Earth. Feel free to do your own estimation. May 1, 2017 at 19:53
• @JamesK Thought you might be interested to see the results of your input. Thank you, I think it turned out rather stunning as well as probably accurate! Jul 24, 2017 at 0:30

It will depend on the face of the Earth that is reflecting the Sun light. It will be a mixture of blue from oceans, white from clouds / poles, brown from deserts and green from forests.

As the Earth has more ocean than land it will usually be dominated by blue (ocean) and white (cloud) making a pale blue.

The light from Earth into space has a blueish colour, and when that light reflects from the Moon and is seen by someone on Earth it is a bit less blue because the lunar surface reflects yellow light more than blue. The net effect is to give us earthshine that is blueish, or turquoise.

You must put it in a spectral histogram program. same color as a shark/manatee according to one crazy program. I found this from basic blur pic from a true color source: and for true color of all planets there was this:

I inputed James K's value into my game for the lighting for my earth lit moon level, and here is what it looks like:

I'd say this is quite beautiful! I realize it would probably be dark enough that we wouldn't see it quite that way, but the robot you control in Planetary Settlers has an enhanced camera to adjust to dark or bright environments. Note that the land is dark grey, but is lit turquoise by the lighting. In this view, you are standing in a sand garden, so the color of that land appears a bit different (starts off light yellow, lit by turquoise light). A big thank you for all of your inputs. If you are interested in learning more about the game I am making, I just made my website for it here: https://jonathanlcopeland.wixsite.com/planetary

The reason the earth is blue is Rayleigh scattering -- same reason the sky is blue. Think of it as a big, faintly glowing blue light bulb.

• I believe you confuse refracted light (the color of the sky) and reflected light (the color of the planet, as seen from the outside).
– DYZ
Dec 24, 2017 at 3:54