SMAS*

[lucy]

Some astrobiologists think that plants on planets orbiting brighter stars than Sol, our sun, are red, yellow, or orange. They think that plants on planets circling stars dimmer than Sol would probably be black. The color of vegetation on other planets matters to astrobiologists because they want to know what to look for as a sign of life. Plants on other worlds probably evolved different colors because they most likely absorb different types of light than the plants on Earth do. The colors of foliage on other planets were determined by the types of light emitted by their sun. Brighter stars than our sun emit more blue, ultraviolet, and green light, so they would reflect red, yellow, or orange rather than blue or green. A star that was only a little dimmer than Sol would probably have a similar light spectrum, and therefore similar plant colors. Planets that orbit red dwarfs would probably absorb visible light, and consequently appear black to the human eye. Photosynthesis on these planets might not derive enough energy to block the harmful ultraviolet light. However, if there were at least 9 meters of water, mats of algae would be protected sufficiently from the dangerous ultraviolet rays. Victoria Meadows of Caltech imagines a peculiar world in which microbial mats of algae float close to the surface most of the time, then sink down to the safer depths of the water when the red dwarf flares. Life could increase once the sun calmed down in its later life.

Original Article: For plants on alien worlds, it isn't easy being green

*= Science Magazine Article Summaries

[mec27]

Lucy thats fasinating, but also highly confusing for me! I don't really get it!!!

[3796enl]

exactly my reaction, thats why i didnt respond. you were very brave to leave a comment

[mec27]

Thank you!!!

[LUCY101]

It was great, lucy, but i didn't really understand it.