Purple Bacteria as Dominant Exoplanet Biosignatures: Expanding the Infrared Palette Beyond Earth’s Green

To the point

Researchers at Cornell’s Carl Sagan Institute, led by Lígia Fonseca Coelho and Lisa Kaltenegger, propose that purple bacteria, which use infrared light and do not release oxygen, could dominate life on many exoplanets and leave bold purple signatures on their surfaces, expanding the search beyond Earth’s green life by cataloging pigments and modeling how different environments and stars, especially cooler red dwarfs, would reflect those colors.