The matter in summary: 3.26 billion years ago, life had just begun to emerge in the ocean, with single-celled organisms as the only life forms. A giant meteorite, called S2, hit what we now know as South Africa, causing a huge tsunami and warming the atmosphere. Despite its devastating effects, this meteorite may have contributed to the development of life on Earth by bringing phosphorus and iron-rich water from the ocean depths to the coastlines. This led to a “baby boom” of bacteria that could make use of iron and phosphorus. Scientists are now investigating other similar events to get a clearer picture of this potential “fertilizing effect”. The summary is made by an AI service from OpenAI. The content is quality assured by news’s journalists before publication. You did not live 3.26 billion years ago, but if you had you would have experienced the following: You are the only human on Earth. The only living thing on earth. Apparently the only living thing on the entire planet. But in the ocean, which at this time covered an even larger area of our planet than it does today, life was just beginning to emerge. “So far” in this context means two things: That life arose only a few hundred million years ago. That the life forms are – let’s be honest – relatively unimpressive. We are talking about unicellular organisms. There is almost no oxygen in the atmosphere, in return there is plenty of methane, ammonia and carbon dioxide. So we have to disregard the fact that you had immediately suffocated. Volcanic eruptions are, if not everyday, a far more common phenomenon than today. You’re probably terribly bored, unless you’re so introverted that you think it’s cool to have the world to yourself. But suddenly something happens. A lump of rock appears in the sky. A huge lump – it’s as big as four Mount Everests. This is what Mount Everest looks like – scary enough to get this in your head, especially when you only have one cell to walk on. Photo: AFP Of course you don’t take the reference since there are still 3.2 billion years until the Indian continental plate will collide with the Eurasian one and form the Himalayas, but you still understand that this is going to be a bit of a bang. When the lump of rock hits what we now know as South Africa and thus changes its name from meteoroid to meteorite, the top layer of the ocean evaporates. Perhaps as much as tens of meters in depth. It gets dark, black clouds of dust block all sunlight. Photosynthesis, the mechanism that allows certain life forms to convert light energy into chemical energy, stops. An enormous tsunami spreads outwards and destroys coastlines across the globe. The air gets warmer, possibly as much as a hundred degrees Celsius warmer. Today, the area looks a lot more peaceful than it must have done immediately after the impact. Photo: Nadja Drabon This must be the end of all life, you think – once again we have to ignore the fact that you had obviously already died in fifty different ways. It wasn’t the end. But could that have been the beginning? The image problem How did the Earth go from being lifeless to being full of life? Did life originate here, or hitchhike already existing life, possibly building blocks that could become life, with intergalactic public transport in the form of comets and meteors? We don’t know, and this is one of the really big questions. Not only because we want to understand where we come from, but because answers to this question will make the job of looking for life beyond Earth much easier. What was it about the conditions on our planet that allowed life to arise? Possibly to develop? Instinctively, it is easy for us to think that giant lumps of rock slamming into the globe at a speed of 20 kilometers per second are destructive to life on Earth. Naturally enough, all the time collisions are generally not considered healthy. In addition, the most famous meteorite of them all ensured that the dinosaurs quickly changed their status from alive, with world domination to dead, but can be successfully used to get children interested in natural science in just under 70 million years. It was here, near Chicxulub, Mexico, that the meteorite that changed the world 66 million years ago landed. And now the dinosaurs have to settle for being statues. Photo: AP This has probably contributed to meteorites that crash into the Earth having a slight image problem. This despite the fact that we might not have had any children to teach science to if our ancestors had to exterminate the tyrannosaurs, spinosaurs, gigantosaurs and velociraptors, it was probably hard enough to break the mammoths The colossus you saw hit the Earth just over three billion years ago , which has been named S2, was much larger than the one that destroyed the dinosaurs, perhaps as much as 200 times larger. Nevertheless, geologist Nadja Drabon at Harvard and her colleagues have found clues that may indicate that this collision did not primarily wipe out life, but allowed life to flourish. Something you can read more about in this report, published in PNAS. No mass death? Drabon and her team have visited the eastern part of the Barberton greenstone belt, north-east of South Africa, several times. There, they comb inaccessible terrain in search of tiny stones. Bitten little stones that can help tell the story of what the enormous collision did to our planet and to the – in a cosmic perspective – newborn life it housed. Nadja Drabon with research colleagues David Madrigal Trejo and Öykü Mete. Photo: Nadja Drabon – Surprisingly, we found no clear signs that the collision caused mass death. We still believe that mass death took place, it is difficult to imagine anything else, but probably the period in which lives died in large numbers was too short for us to be able to register it in the rock material, Drabon tells news. However, what they have managed to record, with the help of chemical analyses, is the fertilizing effect the collision has had. The researchers believe that iron-containing water from the ocean depths has washed in over coastlines, at the same time that the giant stone brought with it plenty of phosphorus from wherever it came from. The result was a solid baby boom with bacteria that could make use of precisely iron and phosphorus. – This sudden shift, in favor of bacteria that prefer iron, can be an important puzzle piece when we try to understand how life developed. Graphics: James Zaccaria Graphics: James Zaccaria Local or global? Jaganmoy Jodder is a postdoctoral researcher at the Department of Geosciences at UiO. There he is associated with the Center for Planetary Habitability, and is particularly concerned with this very topic – how we can understand evolution in the light of what rocks can tell us. – When we talk about whether the impact had a sterilizing or fertilizing effect, we must remember what the conditions on the planet were like at the time. Volcanic eruptions, greenhouse effect, ultraviolet radiation – all this played a role. He says that the meteorite that contributed to the fact that the dinosaurs are no longer among us did not operate in a vacuum either. Several hundred thousand years of massive volcanic eruptions during the same time period probably also played a role. – We must study more similar impact areas elsewhere in the world, so that we get a clearer picture of the global impact, and not just the local one. And that is exactly what Drabon is about to do. There are plenty of catchment areas all around. The S2 meteorite was probably particularly large, but Earth was frequently bombarded by space rocks at this time. – We have already started looking at other incidents of the same type. The aim is to find out how common this fertilizing effect may have been. Published 17.11.2024, at 07.57
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The meteorite’s role in the development of life on Earth 3.26 billion years ago – news Trøndelag – Local news, TV and radio
