For millennia, the Earth has been the target of a real meteor shower which has left indelible marks on its history. Although many of these space bodies have caused devastation, they have also played a crucial role in the development of life. Scientists have discovered that some of the largest meteorites to have impacted on our planet may have been responsible for the flowering of life. primitive life forms, such as certain single-celled bacteria. In fact, what initially seemed to be just a cosmic disaster was actually a blessing for the first life forms on Earth.
One of the largest meteorites ever to hit Earth, known as S2, was between 40 and 60 kilometres in diameter, a colossus 200 times larger than the asteroid that caused the extinction of the dinosaurs. This gigantic celestial body fell to our planet more than 3.260 billion years ago and its impact left scars so deep that they can still be traced in geological formations in South Africa, specifically in the Barberton Greenstone Belt.
The impact of S2: Destruction and fertilization
The impact of the S2 meteorite was brutal. It caused a tsunami that swept across the planet, dragging debris and lifting ocean layersParts of the oceans instantly evaporated, while the heat generated caused the water to boil, plunging the planet into darkness for weeks or even months, due to a cloud of dust covering the sky. With surface temperatures close to 100°C, many forms of life developed, especially those that depended on photosynthesis, did not manage to survive.
However, within the apparent devastation was hidden an unexpected gift for the simplest forms of life. The violent tsunami swept away crucial nutrients such as phosphorus and iron from the depths of the ocean to the surface waters. These elements essential for unicellular life strengthened the bacteria of the Paleoarchaic period, allowing them to thrive in an environment that had previously been inhospitable.
The studies carried out by the researcher's team Nadja Drabon, from Harvard University, have shown that the elements released by the impact of the S2 meteorite acted as a kind of "fertilizer bomb," enriching the primitive seas with the compounds necessary for the evolution of new life forms.
Other meteorites and their influence on Earth's evolution
The S2 meteorite was not the only one. Throughout the history of our planet, large asteroids have repeatedly impacted the Earth, such as the famous Chicxulub, responsible for the extermination of the dinosaurs 66 million years ago. However, as recent studies have confirmed, many other meteorites fell before and after, some causing global cataclysms, but others, like S2, gave rise to new opportunities for life.
Interestingly, in addition to helping bacteria thrive, some of these meteorites came from very specific places in the Solar System. A recent and significant scientific discovery has managed to trace the origin of the 70% of meteorites that end up here on Earth. These studies have confirmed that the vast majority of them come from the asteroid belt between Mars and Jupiter, a place full of fragments of celestial bodies, many of which were thrown into space after gigantic collisions.
The origin of meteorites: Keys to understanding the Solar System
Research led by astrophysicist Miroslav Brož has allowed us to identify that the asteroid families from which most of the known meteorites come are Massalia, Koronis and Karin. These groups were formed as a result of collisions in space millions of years ago, and are responsible for most of the material that reaches Earth in the form of meteorites. In particular, the Massalia family is the origin of more than 37% of meteorites that our scientists have been able to classify.
These asteroids are composed of ordinary chondrites, a type of meteorite that represents the bulk of the material found on Earth. Chondrites are divided into two types: H-type, with high iron content, and type L, with low iron contentThese rocky bodies have been traveling through space for decades, and their impact here has helped us discover part of the history of the Solar System.
The importance of meteorites in the history of life
The latest research continues to provide fascinating insights into the role that meteorites played a role in evolution of life on Earth. What initially seemed to be a chain of catastrophes has turned out to be key to the development of our planet as we know it. From the bacteria that proliferated after the impact of S2 to the studies that reveal the origin of these celestial bodies, we have learned that meteorites not only brought destruction, but also helped create ideal conditions for life in our primitive oceans.
The study of meteorites remains fundamental not only to understanding how life arose on Earth, but also to anticipating the behavior of future celestial bodies approaching our planet. Lessons from the past, such as the fertilization produced after the S2 impact, guide us towards a greater understanding of how these fragments of space have shaped our world and will continue to do so in the future.