Non-green Plants on Extrasolar Planets
Doug Cummings created this graphic showing what foliage colors on another world could look like. (Doug Cummings/Caltech/NASA)
Autumn foliage colors throughout the year? Many science fiction films depict foliation as being green. However, studies on plants have shown that the nature of the sunlight that reaches a plant influences that plant’s color.
On earth, for example, plants photosynthesize mostly on red and on blue light. They also use some of the green light. Then, most of the green light is reflected. What if the host star is red? If the plants on the habitable planet photosynthesize on visible light, then the red light would be used for photosynthesis. Scientists theorize that plants would mostly be black in this scenario.
On the other side of the coin, they also theorize that plants on planets orbiting bright blue stars might use all the blue light to photosynthesize. They would reflect the other colors. So, forests could theoretically consist of trees in different shades of red, orange, yellow, and green throughout the year.
From NASA.gov:
Kiang and her colleagues calculated what the stellar light would look like at the surface of Earth-like planets whose atmospheric chemistry is consistent with the different types of stars they orbit. By looking at the changes in that light through different atmospheres, researchers identified colors that would be most favorable for photosynthesis on other planets. This new research narrows the range of colors that scientists would expect to see when photosynthesis is occurring on extrasolar planets. Each planet will have different dominant colors for photosynthesis, based on the planet’s atmosphere where the most light reaches the planet’s surface. The dominant photosynthesis might even be in the infrared.
“This work will help guide designs for future space telescopes that will study extrasolar planets, to see if they are habitable, and could have alien plants,” said Victoria Meadows, an astronomer who heads the VPL. The VPL team is using a suite of computer models to simulate Earth-size planets and their light spectra as space telescopes would see them. The scientists’ goal is to discover the likely range of habitable planets around other stars and to find out how these planets might appear to future planet-finding missions.
If plants use infrared for photosynthesis, and they reject all visible light, then we have the potential of a forest consisting of trees and other plants that are each dominantly red, orange, yellow, green, blue, violet, and other visible colors.
NASA has the full details for this article here.
Category: NASA
Can this be tested?
Can someone put a plant in a controlled environment with only one type of light to se what happens?
Its not the same as evolving under a different sun, but it might be possible to evaluate the effect of light on photosynthesis.
Good point and idea Brother. I think adaptaion takes a while to happen though.
From UC Santa Barbara on the subject:
http://scienceline.ucsb.edu/getkey.php?key=2679
Excellent link.
I didn’t know that.
And some info on star colors and what they mean:
https://socratic.org/questions/what-does-the-color-of-a-star-indicate
https://courses.lumenlearning.com/astronomy/chapter/colors-of-stars/
Sol (our Sun) is a yellow star with am temp of about 6000 Kelvin
If the sun were yellow, the moon would look yellow. But, the sun isn’t yellow but is nearly a white star. It peaks out between blue and green, and release most of its energy in the green portion of the visible spectrum.
The sun “looks” yellow for similar reason to why it “looks” orange and “red”.
I’ve trained my eyes to see the sun’s green light (hues detected in white objects and in the clouds).
So, whenever I catch a glimpse of the sun, it appears white with olive green hues. This, in tern, made it easier for me to see more shades of green in the foliage than what I used to be able to see.
I remember when I started seeing the sun as white with olive green hues… It was like I traveled to another world. But, what happened was that my perception changed.
Seeing the sun’s green light bounce around on the spring and summer foliage is like watching the sun’s orange or red lights bounce around on Autumn foliage.
A starting point for a very deep rabbit hole:
https://en.m.wikipedia.org/wiki/Main_sequence
https://en.m.wikipedia.org/wiki/Stellar_evolution
Our “yellow dwarf” Sun is about 4.5 billion years old, and is approximately in the middle of its expected lifespan.
When it reaches senility, it will flare up into a red giant, for a fairly short while, then dwindle down to a white dwarf.
Smaller red dwarfs are extremely efficient with their fuel, thus have extraordinary life spans, from one to ten -trillion- years.
The ones that start off as giants? Short life ( as little as a few million years) and spectacular exit – they explode. In the process of building up and then going supernova (boom) they make all the elements we know, and scatter the result into the cosmos.
Where it condenses into stars and planets – and eventually makes us.
The Almighty works in amazing ways.
There’s a phrase, or saying, about people looking at stars as pieces of dead stars looking at living stars.
As Carl Sagan used to say, “We’re all made of star stuff”.
The article mentions the colors of different Earth vegetation depending on their location. For example, underwater vegetation in depths that don’t receive as much sunlight as the surface does.
Green is most efficient at low light levels, thus the advantage of it. But other colors work well enough. some Japanese Maples are red leafed.
https://baynature.org/article/photosynthesis-in-leaves-that-arent-green/
Most plants tend to reflect most of the sun’s green light and use the red and blue lights, and some of the green light.
We have trees in my area that are red/maroon leafed. Even some of our bushes sport red/maroon leaves… I would say these trees are common throughout the US.
“Picture yourself in a boat on a river
With tangerine trees and marmalade skies
Somebody calls you, you answer quite slowly
A girl with kaleidoscope eyes
Cellophane flowers of yellow and green
Towering over your head
Look for the girl with the sun in her eyes
And she’s gone”
put to music:
https://youtu.be/mgNYK96lQOg?t=12
For the 7th grade science fair I experimented
with injecting food coloring into plants to see
if it changed the color of the flowers.
My mom was a nurse and let me use a syringe she had.
The plants all turned brown and died.
Red die #7? 🙂
There is a visual phenomena at sea known as “The Green Flash.”
Read the entire article here: Live Science Link
I’ve never had the opportunity to see it, but I’m told pilots can briefly sustain the green flash by increasing altitude to maintain the required angle.
One time, as I was leaving my neighborhood, the sun broke through the clouds. I saw its green light surrounding its white with olive green hued colored disk.
What kind of mushrooms were really on that pizza, hmmm?
*grin*
Sounds like that was a form of the green flash- cool.
A few years ago, I trained my eyes to see the sun’s green light via reflected sunlight from white objects. Now I see it naturally. The sun appears white with olive green hues to me, and I could spot its green light naturally.
It’s slight, but it’s there.
In Basic we were taught to see
everything as green.
Don’t smoke the orange plants, in fact don’t smoke any of them. Please send to my poz for immediate disposal.
I will need a bottle of Kentucky’s finest too.
Much appreciate.
Cool!