In our quest to discover strange new life on strange new worlds, a group of astronomers has modeled potential alien worlds using Earth’s biological history as a framework. From this they have determined that if we are to detect extraterrestrial biology, we should fine-tune our search to the color purple. . . .
ANALYSIS: Purple Plants Might Thrive Under Multiple Stars
When looking for Earth-like worlds, the researchers emphasize the need for exoplanet hunters to be aware that they may not discover a modern-looking Earth-like world, they may stumble across a purple bacteria-dominated world with a very distinctive photometric signature more fitting with an ancient Archean eon Earth-like world.
“Earth is the only planet where life is known to exist; thus observations of our planet will be a key instrument for characterization and the search for life elsewhere. However, even if we discovered a second Earth, it is very unlikely that it would present a stage of evolution similar to the present-day Earth.”This isn’t the first time that purple alien worlds have been discussed as a possibility. In 2011, researchers examined the exotic energy-generating regimes hypothetical alien plant life would need to develop under sunlight from binary stars.
Over 25 percent of sun-like stars and 50 percent of red dwarf stars exist in binary pairs. Should there be any planets in orbit around binary systems, any life — be it flora or fauna, or some alien form of life that we can’t comprehend, let alone categorize — would be exposed to a broad spectra of light, stretching far into ultraviolet wavelengths. The upshot of this would be purple hued (or even black) plant life that has evolved to optimize photosynthesis. . . .
