Red plants 'could exist' on other planets
Wednesday, 11 Apr 2007 14:51
Other planets' plants could be red rather than green
In Focus
Join the fight against childhood obesity by logging on to our webchat. Full Story
Green, yellow or red-dominated plants may live on other planets, Nasa scientists claim.
Writing in the journal Astrobiology, they describe how they developed a way of predicting the colour of plants on planets in other solar systems.
After studying the light reflected and absorbed by plants on Earth, the researchers argue that if astronomers were to look at light given off by planets orbiting distant stars, they might predict that most planets have mostly non-green plants.
"This work broadens our understanding of how life may be detected on Earth-like planets around other stars, while simultaneously improving our understanding of life on Earth," said Carl Pilcher, director of the Nasa Astrobiology Institute.
"This approach – studying Earth life to guide our search for life on other worlds – is the essence of astrobiology."
Victoria Meadows, an astronomer from the Virtual Planetary Laboratory, added that the study "will help guide designs for future space telescopes that will study extrasolar planets, to see if they are habitable, and could have alien plants".
At the heart of the study is photosynthesis – the process by which plants absorb sunlight and convert it into energy. On Earth plants use red light emitted from the Sun for this process and do not need to use extra green light – therefore the part of the plant which absorbs light (chlorophyll) appears green.
But not all stars have the same distribution of light colours as our Sun, so photosynthesis on planets outside of our solar system may not produce the same colours.
"It makes one appreciate how life on Earth is so intimately adapted to the special qualities of our home planet and Sun," concludes the study's lead author Nancy Kiang.
