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On February 14, 1990, 6,000 million kilometers from Earth, the Voyager 1 He took a photo. There, sustained in space by the mysterious forces of. Space-time, our planet is nothing more than a light blue motor between the sunlight reflected by the camera.
Four years later, Carl Sagan baptized that photo as “that pale blue point.” What we just discovered is that it was not always the case. 3,000 million years ago, that point would have been green.
Wasn’t it blue? Actually, according to Taro Matsuo and his team from the University of Nagoya in Japan explain in Japanduring most of the history of the earth its surface would not have been blue. For about 3,000 million years and until 600 million years ago (just when complex life begins on the planet) the predominant color seems to have been green.
(No) take iron from the matter … The first is that, at that time, the indications tell us that the oceans were full of iron hydroxide. This inorganic compound absorbs blue light. In addition, naturally, water absorbs red light. That means that taking into account that chemical composition, the only free light was the green color.
The other reason is the cyanobacteria. It’s about One of the first photosynthetic beings of history and not only used chlorophyll to absorb sunlight, but used fuses to absorb red and green light. The sum of these two things caused the seas to have a characteristic green color.
And they had it for billions of years. It is true that it was not a pure green color. After all, blue is “a consequence of dispersion Rayleight of sunlight in the atmosphere. “So the color would tend to blue, but without a doubt it would be something much greener than current.
What is the use of all this research? First, to understand that when The MIT explained in 2019that the sea will return green in the mid -century, we are talking about something very plausible. It is not just that A follow -up study In 2023 he confirmed that more than half of the land surface had gained greenery in recent years. It is that, for a long time, it was so.
On the other hand, it allows us to answer one of the great questions of astrobiology: “Does only the blue tone of a planet serve as an indicator of its potential to house life?“And the answer, of course, is no: not a ‘non -radical’ is true; but one that reminds us that there are more things out there that can still dream our biology.
Image | Georgetan#5
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