Giant Meteorite Boiled Oceans 3.2 Billion Years Ago, Creating a ‘Fertilizer Bomb’ for Life

Saima Baig chemistry, evolution, Nature-Environment, News, Science
AI generated image of a giant asteroid hitting Earth
AI generated image of a giant asteroid hitting Earth
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Imagine a huge rock from space! Millions (66 million to be exact) of years ago, such a rock crashed into Earth with a boom that shook the whole planet. It was so big that it wiped out lots of creatures, including the dinosaurs.

But get this: there was an even bigger crash billions of years ago! This one was so powerful that it caused a huge mess all over the world. Scientists think that this big crash might have actually been good for some of the earliest life on Earth.

You see, when the rock hit, it released special nutrients like iron and phosphorus. These nutrients helped tiny, single-celled organisms, like bacteria, to grow and thrive. It was like a giant fertilizer bomb that helped life on Earth to get started!

In a new study researches analysed the effects of this asteroid by using evidence contained in ancient rocks from northeastern South Africa, a place called the Barberton Greenstone Belt. From geochemical signatures of preserved organic material and fossils of marine bacteria, they assessed that life bounded back pretty quickly. In fact it flourished.

“Life not only recovered quickly once conditions returned to normal within a few years to decades, it actually thrived,” said Harvard University geologist Nadja Drabon, lead author of the study published on Monday in the journal Proceedings of the National Academy of Sciences.
The time period when this occured is known as the Paleoarchean Era, when meteorite impacts were not only more frequent but were larger too.
“At this time, Earth was something of a water world, with limited emergence of volcanoes and continental rocks. There was essentially no oxygen gas in the atmosphere and oceans, and no cells with nuclei,” Harvard geologist and study co-author Andrew Knoll said.
According to Drabon, the meteorite was a carbonaceous chondrite (rich in carbon and containing phosphorus), with a diameter of approximately 23-36 miles (37-58 km). This made it about 50-200 times the mass of the asteroid that wiped out the non-avian dinosaurs.
“The effects of the impact would have been quick and ferocious. The impactor hit with so much energy that it and whatever sediment or rock it hit vaporized. This rock vapor cloud and dust ejected from the crater would have circled the globe and turned the sky black within hours,” Drabon said. “The impact likely occurred in the ocean, initiating a tsunami that swept across the globe, ripping up the sea floor and inundating coastlines. Lastly, a lot of the impact energy would get transferred into heat, meaning that the atmosphere started heating up so much that the upper layer of the oceans started boiling.”

It would have taken a long time for the atmosphere to cool down enough for the water vapor to return to the ocean. Microbes that depend on sunlight and those in shallow waters would have been wiped out.

But the meteorite would have brought a lot of phosphorous, a nutrient that microbes need to survive. The tsunami would have also mixed iron-rich deep waters into shallower waters, creating an environment that is perfect for many types of microbes because iron provides them with an energy source.

Evidence of the impact included chemical traces from the meteorite, small spherical formations created from rock melted by the collision, and chunks of seabed debris mixed with other materials stirred up by the tsunami and preserved in sedimentary rock.

“Imagine these impacts to be giant fertilizer bombs,” Drabon said. “We think of meteorite impacts as being disastrous and detrimental to life – the best example being the Chicxulub impact (at Mexico’s Yucatan Peninsula) that led to the extinction of not only the dinosaurs but also of 60-80% of animal species on Earth,” Drabon said. “But 3.2 billion years ago, life was a lot simpler.” “Microorganisms are relatively simple, versatile, and they reproduce at fast rates.”
“Early life was resilient in the face of a giant impact,” Drabon added.

I am a Chartered Environmentalist from the Royal Society for the Environment, UK and co-owner of DoLocal Digital Marketing Agency Ltd, with a Master of Environmental Management from Yale University, an MBA in Finance, and a Bachelor of Science in Physics and Mathematics. I am passionate about science, history and environment and love to create content on these topics.

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