The Earth Might Have Looked Completely Different in the Past and We Don't Know How to React to This News

There have been several theories about how the Earth looked in the past and how it appears today, including some conspiracy theories regarding its true shape. Some people claim that the Earth is flat, while others argue that it is squashed. However, the flat Earth theory is definitely false, and the latter has been confirmed to be true. While our beloved planet is not a perfect sphere, it is important to note that it is classified as a geoid.

Given that the Earth has existed for billions of years, our imagination can stretch far when considering its appearance in the past, especially in light of how much it has evolved based on scientific studies. Would you believe the Earth had a completely different color during its early days? Can you imagine a purple Earth from outer space? A study supported by NASA suggests that this may be true.

In a study published in the Astrobiology journal by Cornell University, researchers uncovered findings that suggest the Earth was not the blue and green planet we recognize today. This concept, known as the Purple Earth hypothesis, proposes that single-celled organisms back then depended on a simpler molecule than chlorophyll to harness sunlight.

Astrobiologist Dr. Edward Schwieterman from the University of California, Riverside — together with his colleagues — conducted this study and developed the concept.

So, what exactly made the Earth purple according to the study? Thankfully, it’s not as complicated as it sounds. Unlike modern plants that rely on chlorophyll, scientists believe that sunlight was abundant enough to support these purple microbes at the time. During that time, plants supposedly did not use chlorophyll for photosynthesis because oxygen was believed to be scarce. Therefore, the Earth was not as lush and green back then as it is today.

Over time, organisms evolved to use the more efficient pigment, chlorophyll, which allowed them to harvest sunlight at stronger wavelengths. This shift overshadowed the retinal-based approach and contributed to the Great Oxygenation Event, when oxygen levels in our atmosphere increased dramatically. While retinal-based life did not disappear, it was no longer the dominant force shaping the planet’s surface color.

As chlorophyll-using organisms thrived, Earth’s appearance changed from purple to green. Despite this transformation, astrobiologists still believe that exoplanets could potentially host life forms that rely on retinal-based processes.

Today, while Earth is predominantly green, there are places like the Dead Sea that still exhibit violet hues, thanks to halobacteria. These bright purple microbes can be found in highly salty environments, such as the Great Salt Lake.

Although the notion of a purple Earth has yet to be definitively proven, its potential, once verified, could reshape our understanding of Earth’s past and the search for life beyond our planet. You might wonder whether this study is necessary.

The answer is yes. For one, it could help researchers find answers about exoplanets. Secondly, it would enhance our understanding of how life could survive in similar conditions elsewhere. Overall, it’s an exciting discovery that can provide insights into our evolutionary future.

Indeed, this is more than just a study; it serves as a metaphor for humanity's ability to adapt. It conveys an inspiring message that change is constant and that we can overcome challenges if we learn to adapt.