The majority of the planet’s land masses are green, despite the fact that the Earth is sometimes referred to as “the Pale Blue Dot” because of its abundant oceans. Through a process called photosynthesis, plants employ chlorophyll—which reflects green light while absorbing red and blue light—to absorb solar energy and use carbon and water to generate food.

The primary means by which plant life exists on Earth is described in this biology lesson for fourth graders. However, life on other exoplanets that resemble Earth, particularly those that orbit red dwarf stars, may employ a completely different strategy that would cause the entire planet to turn purple.

Researchers at Cornell University examined how extraterrestrial plants that use infrared light for photosynthesis can change the color of their surroundings.

These bacteria, which include phototrophic anoxygenic bacteria and photoheterotrophic bacteria, may release a characteristic “light fingerprint” that future observatories, such as the Extremely Large Telescope at the European Southern Observatory, may be able to identify. The study’s findings were released in the Monthly Notices of the Royal Astronomical Society publication.

According to a press release from Cornell University Ph.D. student Lígia Fonseca Coelho, “purple bacteria can thrive under a wide range of conditions, making it one of the primary contenders for life that could dominate a variety of worlds.” “They already thrive here in certain niches… just imagine if they were not competing with green plants, algae and bacteria: A red sun could give them the most favorable conditions for photosynthesis.”