The red red grass of home..!

[Che Guava]

An interesting little bit...

Colorful Worlds: Plants on Other Planets Might Not Be Green

By Ker Than
Staff Writer
posted: 11 April 2007
09:01 am ET


If trees grow on other planets, their leaves might be red, orange or yellow, and not only in autumn, scientists say.

Two new studies detailed in the March issue of the journal Astrobiology find that the color of a planet’s photosynthetic organisms depend on the type of star the world orbits and the makeup of its atmosphere.

“You have a particular spectrum which is affected by the star’s surface temperature, but once that light comes down through the atmosphere, the atmosphere filters that radiation,” said study team member Victoria Meadows of the Virtual Planet Laboratory (VPL) at Caltech.

For example, our Sun radiates most of its energy in the green part of the visible spectrum. But ozone molecules in the Earth’s atmosphere absorb much of this green light energy, allowing other colors, especially red, to filter through to the ground.

This could explain why chlorophyll absorbs mostly red and blue light and reflects green light, the researchers say.

“Ozone filters out some of the blue-green radiation, so there’s less of that available at the surface of the planet,” Meadows told SPACE.com.

Alternative explanations have also been proposed for the greenness of plants. One idea, called the purple Earth hypothesis, states that chlorophyll doesn’t absorb green light because it appeared after another pigment, called retinal, was already present and it had to settle for the “leftover” wavelengths that were not being absorbed.

The researchers reached their conclusions after analyzing 12 different kinds of light-sensitive pigments, including chlorophyll, that organisms on Earth use to harness the Sun’s energy.

Plant biosignatures

The researchers want to use their findings to guide the search for plant life on other worlds. To that end, Meadows’ team at VPL entered the results of the pigment analysis study into a computer simulation that predicts what the light from a distant planet containing photosynthetic organisms will look like to space telescopes.

For example, in addition to reflecting back visible green light, organisms on Earth that use chlorophyll for photosynthesis also reflect near infrared light. This reflected light can be seen from space and is called the “red edge.”

The new findings suggest photosynthetic organisms on other planets might not produce a red edge, but some other biosignature instead. The researchers want to figure out what those alternative biosignatures might be.

“We’re coming up with rules so that we can say more confidently what is photosynthesis when looking at spectra from these planets,” said study leader Nancy Kiang, a biometeorologist at NASA’s Goddard Institute for Space Studies in New York.

Search for life

Whether or not scientists find life on distant worlds could depend on these rules.

“When we look at these faraway planets, we’re not going to be able to spatially resolve them. We won’t be able to see continents and oceans,” Meadows said. “Everything we must learn about that planet will be in a single dot of light.”

Already, the researchers think they can already make certain generalizations about photosynthesis in the universe at large. It’s unlikely, for example, that plants on alien worlds will be blue.

“It appears that harvesting blue light is very common across the board for photosynthetic organisms” on Earth, Kiang said in a telephone interview. “I think it is unlikely that anything will be blue.”

link

Funky, no?

 

[Xanikk999]

A more interesting question is why would life evolve the same way to resemble that?

Life would adapt to a whole assortment of conditions, not just the light.

Take into account gravity, levels of various gases in the atmosphere, ect..

 

[Taliesin]

Actually, that picture looks pretty plausible for Earth, especially if you removed the palm trees and made the sky blue. I think that might have something to do with my colour-blindness, though.

 

[Che Guava]

Still, as sunlight is probably the largest, most regular and powerful energy source most planets capable of supporting life would have, it wouldn't be too much to assume that there would be an equivilent of plants on most planets wih developped ecosystems...

 

[Urederra]

Well, we already have Red and blue-green algae. And they have those colors because they have a precursor of the photons catching molecule chlorophylla that has those different colors.

BTW, is this a racist thread?

 

[Xanikk999]

Well, we already have Red and blue-green algae. And they have those colors because they have a precursor of the photons catching molecule chlorophylla that has those different colors.

BTW, is this a racist thread?

Well algae are not plants, they are usually multicellular protista but NEVER plants.

 

[Che Guava]

BTW, is this a racist thread?

Absolutely. Damn those red plants and thier freaky spicy foods! Go back to the planet you evolved on, reddies!

 

[Perfection]

Well, we already have Red and blue-green algae. And they have those colors because they have a precursor of the photons catching molecule chlorophylla that has those different colors.

I'm not sure if they were actually precursors of coevolutionary (Cyanobacteria is really old after all), but what I really want to note as cool is the fact that the different pigments have dominance in different ocean depths and so even on Earth this reigns true.

 

[StarWorms]

I thought this would be pretty obvious...

 

[Elrohir]

Why do they have a journal of Astrobiology when there is no actual evidence that life exists outside of the Earth? Speculation is all well and good, and I think it's certainly possible that there is life out there - but isn't that sort of of jumping the gun?

Anyway, cool concept, I guess. Although if the best thing the universe has to offer is red-leafed trees, I'll be disappointed.

 

[Xanikk999]

Why do they have a journal of Astrobiology when there is no actual evidence that life exists outside of the Earth? Speculation is all well and good, and I think it's certainly possible that there is life out there - but isn't that sort of of jumping the gun?

Anyway, cool concept, I guess. Although if the best thing the universe has to offer is red-leafed trees, I'll be disappointed.

Read the damn thing, its not just speculation.

About life existing outside earth is irrelevent. They just said that the plants might have different types of photosynthesis receptors that might not be green like most plants because of the different wavelenghts of light from other stars. (I dont think i explained that well. )

 

[Che Guava]

Why do they have a journal of Astrobiology when there is no actual evidence that life exists outside of the Earth? Speculation is all well and good, and I think it's certainly possible that there is life out there - but isn't that sort of of jumping the gun?.

True, but then again they have journals of theology too, don't they...?

Anyway, cool concept, I guess. Although if the best thing the universe has to offer is red-leafed trees, I'll be disappointed

I'm sure theyll be some freaky-deaky aliens munching on those red-leaf'd trees...maybe a purple moose?

 

[Abaddon]

respect Xan to your first post.. i hadn't thought such an obvious but vitally imporant thing

 

[Elrohir]

Read the damn thing, its not just speculation.

About life existing outside earth is irrelevent. They just said that the plants might have different types of photosynthesis receptors that might not be green like most plants because of the different wavelenghts of light from other stars. (I dont think i explained that well. )

"If trees grow on other planets, their leaves might be red, orange or yellow, and not only in autumn, scientists say." This is speculation, not fact. Until you can show evidence that this is so, it's speculation. They may very well be right - but it's speculation until they can show that they are.

Life existing outside of the Earth is relevant as to why we have a journal on something which can't be proven to exist.

True, but then again they have journals of theology too, don't they...?

Touche. There is a difference, however: It's ultimately provable using science that these things do exist. (Proving that they don't would be too hard, however) Science cannot, however, prove that God does or does not exist. They aren't quite the same, but it's a good response anyway.

I'm sure theyll be some freaky-deaky aliens munching on those red-leaf'd trees...maybe a purple moose?

That'd be pretty sweet.

 

[Xanikk999]

Dude the wavelength thing with the color of the leaves is not just pure speculation.

Scientists dont speculate out of thin air. They have a bit of evidence and knowledge to back it up on.

Granted i dont know what they mean by it. They wouldnt be just making things up and saying it "could" be like this without any meaningful reason.

Thus its not just speculation.

 

[Elrohir]

Dude the wavelength thing with the color of the leaves is not just pure speculation.

Scientists dont speculate out of thin air. They have a bit of evidence and knowledge to back it up on.

Granted i dont know what they mean by it. They wouldnt be just making things up and saying it "could" be like this without any meaningful reason.

Thus its not just speculation.

speculation

noun
1. a message expressing an opinion based on incomplete evidence [syn: guess]
2. a hypothesis that has been formed by speculating or conjecturing (usually with little hard evidence); "speculations about the outcome of the election"; "he dismissed it as mere conjecture"
3. an investment that is very risky but could yield great profits; "he knew the stock was a speculation when he bought it"
4. continuous and profound contemplation or musing on a subject or series of subjects of a deep or abstruse nature; "the habit of meditation is the basis for all real knowledge"

There is no hard evidence that extraterrestrial life exists, much less that it exists like this. They may very well be right - but they can't prove that they are. This is a very nice hypothesis, but it's just that. It's an idea of how it could be, not a fact. I'm not saying that they are saying something they know to be wrong - I'm saying that they cannot prove that they are right.

 

[Xanikk999]

speculation

noun
1. a message expressing an opinion based on incomplete evidence [syn: guess]
2. a hypothesis that has been formed by speculating or conjecturing (usually with little hard evidence); "speculations about the outcome of the election"; "he dismissed it as mere conjecture"
3. an investment that is very risky but could yield great profits; "he knew the stock was a speculation when he bought it"
4. continuous and profound contemplation or musing on a subject or series of subjects of a deep or abstruse nature; "the habit of meditation is the basis for all real knowledge"

There is no hard evidence that extraterrestrial life exists, much less that it exists like this. They may very well be right - but they can't prove that they are. This is a very nice hypothesis, but it's just that. It's an idea of how it could be, not a fact. I'm not saying that they are saying something they know to be wrong - I'm saying that they cannot prove that they are right.

They are not arguing about the existence of extraterristrial life... sheesh.

Its if it did exist, this is what the alient plants might look like.. based on some evidence.

 

[Urederra]

Scientists dont speculate out of thin air. They have a bit of evidence and knowledge to back it up on.

From http://www.bbc.co.uk/science/space/life/looking/

Scientists have wondered whether creatures like jellyfish could survive on Jupiter or Saturn, feeding on organic material in the clouds. However, no evidence has yet been found that such creatures exist.

 

[Xanikk999]

Ok there are stupid scientists, but what do you expect, the guy on the right is from SETI. Thats thier goal.

 

[Elrohir]

They are not arguing about the existence of extraterristrial life... sheesh.

Its if it did exist, this is what the alient plants might look like.. based on some evidence.

"If trees grow on other planets, their leaves might be red, orange or yellow, and not only in autumn, scientists say."

Either they are speculating, or they have proof saying that this is true. They have evidence saying that if there is alien life, then they might be like this. I don't understand what is so difficult about this. That they are speculating doesn't mean that they are wrong, it just means they haven't proven it right, yet. Speculation isn't a bad thing.