About 3.26 billion years ago, a meteorite of colossal proportions struck Earth—not the one that wiped out the dinosaurs, but one 50 to 200 times larger. According to a recent study published in the Proceedings of the National Academy of Sciences, this cataclysmic event may have triggered the planet’s first life forms.
A little context. Earth looked very different 3.26 billion years ago during the Archean Eon. Only single-celled organisms like bacteria and archaea existed. The oceans, possibly green from iron, were nutrient-poor and largely biologically barren.
Giant meteorites bombarded Earth during this era, with at least 16 impacts exceeding 6,000 miles in diameter. Among them, the S2 meteorite stands out.
The colossal S2 meteorite. A Harvard University team, led by planetary scientist Nadja Drabon, has spent recent years studying the possible effects of the S2 meteorite, estimated to have been between 23 and 36 miles in diameter when it hit Earth.
Researchers traveled to South Africa’s Barberton Makhonjwa Mountains to analyze rocks, finding tiny spheres from the impact. These particles allowed them to reconstruct the dramatic events that followed—a violent yet enriching chaos.
The meteorite impact generated a massive tsunami that swept across the planet. The heat was intense enough to boil the surface of the oceans, evaporating vast amounts of water and leaving extensive salt deposits behind.
For years, perhaps even decades, dust from the impact darkened the skies, affecting photosynthetic microorganisms. Meanwhile, the ocean's turbulence released iron and phosphorus, sparking a nutrient boom for bacteria that relied on these essential elements.
Prosperity after disaster. Despite its immediate destruction, the colossal S2 meteorite’s impact ultimately led to the flourishing of single-celled life, researchers suggest, thanks to a rapid nutrient infusion in Earth’s oceans.
Scientists believe the S2 impact acted as a “fertilizer bomb,” enriching marine environments and accelerating life’s evolution at a time when Earth was home only to single-celled organisms. Unlike Chicxulub—the asteroid that ended the dinosaur era 66 million years ago by releasing sulfur and cooling the Earth—S2 delivered nutrients that encouraged the growth of early life.
A noteworthy discovery. This study offers fresh evidence that cosmic impacts may have roles beyond devastation. For Earth, these collisions likely released critical nutrients that fueled early biodiversity and set the stage for complex life, including humans.
The Harvard team plans to investigate additional impact events to determine whether they commonly support life. Their findings could reshape our understanding of meteorites in the evolution of life on Earth and the potential origins of life itself.
Image | Javier Miranda (Unsplash) | Nadja Drabon et al.
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