Could Those Purple Planets Harbor Alien Life?
Most movies show aliens living on beautiful green worlds just like Earth. But a new study says we should keep an eye on planets with a purple hue too! The researcher, Lígia, found that certain bacteria could survive in lots of different places. These "purple bacteria" use special pigments to get energy from light in many wavelengths, not just the colors we see. That makes them more flexible than regular plants. Lígia's paper discusses how to spot purple worlds and why their bacterial life may thrive in places with less oxygen, darkness, or temperature extremes. The bacteria even come in two types - those with purple or green pigments. So don't rule out purple planets just yet in the search for aliens! Their bacterial inhabitants could handle living in more diverse conditions than we expected.
Could We Spot Aliens on Purple Planets?
The cool purple bacteria get their color from special pigments like what gives carrots and tomatoes their colors. Some pigments let them use the colors we can see for energy, while others help them use invisible infrared light. This means they might do really well on planets around red dwarf stars, which are smaller and cooler than our sun.
A team at Cornell wants to find these bacteria on other worlds. They know that certain types could live in places with lots or little oxygen. So the team collected over 20 types of purple sulfur and purple non-sulfur bacteria. They studied the pigments and how the bacteria use light. Then they modeled pretend planets like Earth with different climates and weather. When they added the bacteria data to the models, even the wet or dry bacteria had very colorful signs of life. Now they're making a database of colors and chemicals from different living things like the purple bacteria. This could help spot alien life's colorful "fingerprints" on Purple Planets!