Celestia Forums

Earth is blue and is illuminated by an yellow star, the Sun. How Earth would look like if it were being illuminated by A, F, K and M stars.
I think that Earth would look like if it were illuminated by:

A stars: Earth would be violet instead of blue.
F stars: Earth would be indigo instead of blue.
K stars: Earth would be aquamarine instead of blue.
M stars: Earth would be green instead of blue.

I think this idea can be true because each different types of stars illuminate a planet in different waveleghts.

For example: Earth would be green with M stars because of the low frequency waveleghts that M stars produce. On the other hand, Earth would be violet being illuminated by A stars because of the high frequency waveleghts.

Do you think that it's all true? I think yes. I'm doing a new addon with an Earth-like aquamarine color planet being illuminated by a K8VI star. There is an add-on called Mira System that I think it was made by Rassilon and that have a green Earth-like planet being illuminated by Mira Star, that is red.

Hmmm...

Interesting idea to consider for my upcoming Proxima Centauri addon, do you think this would apply to other worlds as well?

What would change things a bit in Celestia is that red stars give out red coloured light resulting in reddish planets, same for the others, I wonder how this would impact to someone trying to give effects like these?

Michael Kilderry

I don't think it works like that.

When you have a different "colour" star the light given off would still appear white. The difference would probably be the relative brightnesses of different colours on the planet. For bluer stars the blues would be brighter, for redder stars reds would be brighter.

This would probably mean that for stars with temperatures which differ greatly from the sun the greens would be a lot darker relative to the planet, probably appearing almost black from space. The blues would still be blue though.

Whether the oceans are blue probably would depend on the sky colour though, which is a complex issue and has been discussed elsewhere. For an M star one view I've seen here is that the sky and hence the oceans would be greyish, with the clouds appearing yellowish relative to the background sky. For bluer stars the sky might appear deeper blue, so the oceans would be slightly darker.

That's as far as I've been able to figure out. Feel free to correct me if I'm wrong.