Key to Searching for Alien Life Could Lie in Purple Planets, Not Green Ones

Researchers from Cornell University have discovered that certain purple bacterial species may hold the key to finding alien life on distant planets. These bacteria contain carotenoids and bacteriochlorophylls that allow them to harness energy from visible light and the infrared band, respectively. This makes them more likely to exist on planets orbiting cooler M-type stars compared to our sun.

To ensure they do not overlook the presence of these bacterial species on alien planets, scientists at Cornell are compiling a database of colors and chemical signs for a wide range of organisms. By studying over 20 purple sulfur and non-sulfur bacteria, the team has been able to develop models of Earth-like planets with different climates and cloud cover.

By analyzing the reflectance of these purple bacteria in various oxygen levels, the researchers were able to simulate different extraterrestrial environments. The bacteria displayed vibrant colors indicative of life in both hydrated and arid conditions. This research may prove instrumental in the search for alien life outside our solar system.