The space rock that hit Earth 66 million years ago at the end of the Cretaceous period caused a global catastrophe that wiped out the dinosaurs and many other creatures, but it wasn’t the biggest meteorite hit the Earth.
Reuters reported that a meteorite 200 times larger landed on Earth 3.26 billion years ago, causing massive damage. But new research shows that the accident may have actually been beneficial to the first evolution of life, serving as a “giant fertilizer bomb” for bacteria and the single-celled organisms most important to the called archaea, providing access to the main nutrients phosphorus and iron.
Researchers used ancient rock evidence from the Barberton Greenstone Belt in northeastern South Africa to assess the impact of a meteorite impact. They found ample evidence of a strong resurgence of life, particularly from preserved geochemical signatures of organic matter and fossilized marine bacterial carpets.
▲ Researchers used ancient rock evidence from the Barberton Greenstone belt in northeastern South Africa to assess the effects of a meteorite impact. (Source:PNAS)
The report was published in the journal Proceedings of the National Academy of Sciences. “When things return to normal, life not only recovers quickly but thrives within years to decades,” said Nadja Drabon, a paleontologist at Harvard University and lead author of the study.
This impact event occurred during the Paleoarchean era, when Earth was a completely different world and meteorite impacts were larger and more frequent. “At that time, Earth was something of a water world, with a few exposed volcanoes and continental rocks. There was no oxygen in the atmosphere and oceans, and there were no nuclear cells,” said Harvard geologist and study co-author Andrew Knoll. .
This meteorite is a carbonaceous chondrite rich in carbon and phosphorus. Dreben said that the diameter of this meteorite is about 37 to 58 kilometers, and its mass is 50 to 200 times greater than the asteroid that caused the extinction of the dinosaurs. “This impact was likely to be swift and violent,” said Dreben. the universe, causing the sky to turn dark in a matter of hours.”
Dreben said: “This impact could have occurred in the ocean, causing a tsunami to sweep across the world, tearing up the seabed and causing coastal flooding. that the atmosphere began to heat, causing the upper layers of the ocean to begin to boil.”
Dreben said that after a meteorite impact, it may take years to decades for the dust to settle and the atmosphere to cool, allowing water vapor to return to the ocean. Microorganisms that depend on sunlight and micro-organisms of shallow water can be destroyed.
But the meteorite may have brought with it a lot of phosphorus, a key nutrient for molecules that microbes use to store and transmit genetic information. Tsunamis can also mix deep, iron-rich water with shallow water, creating an environment ideal for many species of microorganisms because iron is an energy source.
“We can think of the effect as a big fertilizer bomb,” said Dreben.
He said: “People think that meteorite impacts are disasters and threats to life. The best example is the Chicxulub impact (Yucatan Peninsula in Mexico) which led to Extinction of dinosaurs and 60% to 80% of animal species on earth.Microorganisms were simple and versatile and could reproduce quickly.
(Translator: Zhang Xiaowen; original image source:Pixabay)
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