The color of plants in different kinds of stars

[kikinho]

Hi people!

I've read about an Earth-like planet that orbit red stars can't have green plants. And the ideal color shold be blue, but blue does not appear when illuminated by a red star, and it appears black, and the ideal color should be black, because it absorves more red light than green plants.. This is true?

Now what I really want to know is...

Considering that the star is orange and emmit about 30% of the light compared to Sun, that is 100%.

What is the ideal color of plants in an Earth-like planet orbiting an orange star ( K type, more precisely a K2V star )? I put a color that is between orange and red colors. This is the ideal color? Or is still green?

Here is the color of plants in my planet...



And what is the ideal color for a plant in a planet that orbit F, and if it would be possible, A, B and O stars?

Ps: I prefer to create systems orbiting K stars because this kind of star doesn't emmit so much ultraviolet light and stay in main sequence much longer than Sun.[/img]

[Michael Kilderry]

So this planet must be from your new addon.

For K Stars, the ideal colour for plants would probably be in between green and blue, probably turquoise. The colour would be different though, since it orbits around an orange star. But don't worry about this too much, as Celestia seems to do light colours automatically.

Michael Kilderry

[kikinho]

But what about plants in planets that orbits M, F, A, B, and O stars? Would be yellow, orange or red, or even an infrared pigment?

[maxim]

Kihinko, you should review your landmass creation process. It is quite obvious to a viewer that the topleft african part is different in resolution than some of the other parts. Also your Rocky Moutains part in the middle looks quite 'missplaced'. The size of the mountain foldings gives an implicite 'feeling' for the size and the mismatches between the 'continents'.

Maybe you should use non-preshaded textures, and then apply normal maps in a uniform resolution at the end. This way foldings would look same-sized.

maxim

[Scytale]

One common theory giving an answer to the question "why plants evolved to be green" is as follows : there is a peak in solar radiation intensity in the visible spectrum around yellow-green, and plants reflect that portion of the spectrum in order not to overheat, or overcharge.

The green is clorophile, which is also the molecule producing complex organic compounds from CO2 and oxygene. There are two types of clorophile, each reflecting a certain portion of the spectrum; theory says they started getting closer to green when plants synthetising non-green clorophile were burned out by the solar radiation, because their sensible proto-clorophile molecules broke down into smaller compounds. Thus, by applying evolution theory when stable clorophile appearred, it was green

So, in evolution terms, it's all a problem of energy balance. On a planet orbiting a cool red star, plants or plantoids would barely get enough energy, so they would evolve into black (absorbing the whole spectrum). On a planet orbiting in the inner ecosphere of a hot red star, plants would reflect some portions of the spectrum so that they wouldn't burn down - they would be red, or orange, or magenta. Around white or white-blue stars, you may even get to find bright-grey plants, and so on.

I guess a competent biochemist would shed more light on the subject.

[eburacum45]

One thing we can say with reasonable certainty is the the plants would
not be red.
Probably the plants would be blue-green or black; if the biochemistry is
anything like that of Earth the plants might use the same accessory pigments
as blue-green algae, namely phycocyanins and phycoerythrins.

The light of a red dwarf star is only slightly reddish in any case, similar to the light from an indoor light bulb;
also the Emerson effect causes photosynthesis to be enhanced slightly if there is abundant red light.
The worst problem is likely to be the fact that red light does not
penetrate water very readily, and so the photic zone is likely to be less
deep on planets orbiting cooler stars, which might affect evolution.

Incidentally some bacteria photosynthesise without chlorophyll, in the
near infrared- around 850 nm wavelength. Perhaps this bacterial
photosynthesis will be adopted by higher plants on such planets.

remember too that the habitable zone for cooler stars will be near the
star, and such close planets will tend to be tidally locked- these half and
half worlds will have strange weather regimes.

[kikinho]

My system have a K2V star. My planets are not tided locked because they are of a distance about 0.63 to 0.68 AU, and in this distance they are still not tided locked. And the planet that is of a distance about 0.68 AU have higher atmospheric pressure, so it absorves more heat and don't need to be so much close to i'ts star. The planet that is about 0.63 AU have a less atmospheric pressure, so it can be closer to it's star without super heating.