This mass extinction was caused by a chain reaction of asteroid collisions in the central asteroid belt
By: Birger Schmitz, Professor of Nuclear Physics, Lund University
Something mysterious happened almost half a billion years ago that brought about one of the most important changes in the history of life on Earth. Suddenly an abundance of species filled it, as the biodiversity of invertebrates rose from almost zero to something similar to what we see today. The most popular explanation for the Great Biodiversity Event of the Ordovician Age 450 million years ago is that it was the result of the Earth cooling down from a heat excess to an ice age.
But what actually caused the temperature change? In our new paper, published in Science Advances, we show that the temperature change coincided exactly with the largest recorded asteroid breakup in the asteroid belt over the past two billion years, caused by a collision with another asteroid or comet. Even today, almost a third of all meteorites that fall on Earth originate from the breakup of this asteroid with a diameter of 150 kilometers between Jupiter and Mars.
Following this event, huge amounts of dust were spread throughout the solar system. The blocking effect of this dust could have partially prevented sunlight from reaching the Earth - which could have led to a sharp drop in temperatures. We know that this allowed the division into homogeneous climate zones from arctic conditions at the poles to tropical conditions at the equator. The high diversity among invertebrates, including green algae, primitive fish, and corals, came as an adaptive response to the new climate.
Our evidence comes from detailed studies of Ordovician age (485-443 million years ago) seafloor sediments exposed at Kinkoli in southern Sweden and the Linna River near St. Petersburg in Russia. In the Kinkoli quarry, we found more than 130 "fossilized meteorites" - rocks that fell to earth in the ancient past, which were integrated into the sediments of the seabed and preserved just like animal fossils.
Most meteorites up to 20 centimeters in diameter have the same composition - they are all fragments from the same collision. Indeed, they were composed of the same type of material as the large asteroid that then broke up in the asteroid belt. One meteorite originated from the smaller body that hit the larger asteroid.
We know that the asteroid collision happened 466 million years ago. This can be dated by looking at isotopes (versions of chemical elements with different numbers of neutrons in the nucleus) in meteorites that recently fell from the Ordovician asteroid breakup. The fossilized meteorites in the quarry must therefore represent the material that was transported to Earth immediately after disintegration. And considering the large number of meteorites we found on the bottom of the sea, we can estimate that the meteorite flux to Earth was several orders of magnitude higher at that time than it is today.
But how do we know that this shelling created a huge amount of dust that caused the temperature to drop? We also investigated the distribution of micrometer-sized dust in the sediment layers. We were able to determine that the source is extraterrestrial by locating helium and other substances incorporated into the sediments, which can only be explained by the solar wind bombarding the dust, enriching it with the same elements on the way to Earth.
Our results clearly show that enormous amounts of fine-grained dust reached Earth shortly after the collision. The geological record shows that shortly after the dust arrived, sea levels dropped dramatically around the world - a sign of the beginning of an ice age. The reason for this was that the sea water drained to the high latitudes, where large ice sheets formed.
The result was completely unexpected - in the last 25 years we have been using a variety of very different hypotheses in terms of understanding the events that happened here during this period. For example, while we assumed that the diversity event was somehow related to the asteroid breakup, we believed that many small asteroids that also came to Earth from the breakup caused the changes, not the dust. It wasn't until we got the last helium measurements that everything worked out.
Lessons for climate research
Global warming continues as a result of carbon dioxide emissions, and the temperature increase is greatest in the high latitudes. According to the Intergovernmental Panel on Climate Change, we are approaching a situation reminiscent of the conditions that prevailed before the asteroid collision 466 million years ago. It is clear that continuing in this way will not benefit biodiversity.
In the last decade or so, researchers have discussed various artificial methods for cooling the Earth to mitigate the climate crisis. One solution would be to place asteroids, like satellites, in orbits around the Earth so that they continuously release fine dust and block sunlight.
Our findings show for the first time that such dust sometimes cooled the Earth dramatically. We hope this may be a viable artificial solution. Our studies can provide a more detailed, empirically based understanding of the modus operandi that can be used to create and evaluate computer models of such events.
But for the foreseeable future there is no other way to deal with climate change than to reduce our carbon emissions. Ultimately, this is the only way to preserve the spectacular boost in the diversity of life that has evolved over the past 466 million years.
to the article on The Conversation website
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I believe that it is actually possible to use the asteroids for our benefit if it is a cushion of minerals or for example to place a space station there that uses it for travel and research without the need for expensive fuel, even if they can use its inertial power to produce energy and more...
It is not clear to me: the article refers to the period of meteors 466 million years ago, and the huge variety of species that appeared in Camryon occurred about 500 million years ago?? I'm not an expert in the field, but the relationship between meteors 466 million years ago and the Cambrian explosion is not clear enough, can anyone relate??
This is exactly the problem with the climate debate. Create another party artificially and demand rights for it
Walla! How did these scientists discover my secret??!
I remember waking up one day at about 10 o'clock, I heard a very loud noise, I looked out the window, and you won't believe what my eyes saw. Blocks of rocks with a diameter of 20 to 30 cm fall from the sky, the whole earth shakes, and the whole world is filled with dust.
After a few hours the dust dispersed, and I began to feel an immense cold, after many years of unbearable heat.
I kept this secret to myself until today because I was afraid that I would be hospitalized for daydreaming. This article gave me the urge to come out of the closet and share with you too
In the amazing way.
Only one thing I don't understand, maybe it's because of a typing error, my story was a few years ago, and in the article they talk about 450 million years ago. I don't remember being alive so many years ago, but apparently these scientists did live in that time, otherwise what truths and reliable tests do they decide for us.
I took a hallucinogenic pill and went back to bed, I'm waiting for the people of exact science to tell me more night stories.
Good night, asteroids and fairies!
Avi Blizovsky,
I am really surprised by the style of your replies to the commenters here.
I read the articles on the site regularly, and I would expect from you that if you have a debate on any subject it would be at a level that is suitable for a scientific debate with a willingness to hear another side.
Unfortunately, you responded here in a condescending and irrelevant manner.
I wish an asteroid would destroy my husband's ex-wife and all her offspring. Amen
Everything, everything, theories
Who even knows what happened billions of years ago
You really made me laugh
If an asteroid were to hit the earth at the level that the dinosaurs became extinct, then all mammals and all animals would also be extinct. Forever or there would have been a few species of dinosaurs left...
To say that everything became extinct and millions of years later life developed anew sounds delusional
You can hardly tell what was here 4000 years ago
So to know what was billions of years ago?
In my opinion, in an evolutionary process man developed or was put here by an external factor
We are part of a whole system of universes that together constitute an overall mechanism of something.
With the technology of today and in the future we can cause the same effect for example on Venus to cool it or the Earth.
You are proposing to believe a group of converts who are trying to tattoo science in other fields (e.g. evolution) by joining those who tattoo the field of climate.
"Human-made warming" = false "scientific consensus" - achieved by brainwashing
Below is a quote: "I have come to the conclusion that the unjustified consensus regarding man-made climate change harms the advancement of science because of the questions that are not asked and the issues that are not investigated [because they are contrary to the consensus]. Therefore, we lack the information that would allow us to better understand climate change and society's vulnerability to it."
https://rationalbelief.org.il/קונצנזוס-מדעי-שקרי-שמושג-עי-שטיפת-מח/
In light of the five major extinctions, it seems that those who care about life on Earth are the asteroids. Now the sixth extinction comes from an inner asteroid.
Those who have taken care of life on earth until now, will continue to take care of it in the future...
There is no way anyone would allow dust to be released near the Earth, where it would sabotage all the satellites placed in different orbits and at different heights around the Earth. Introducing dust to the Lagrange point 1 (located between the Earth and the Sun) is also out of the question, and in any case, what they put there will soon disperse and again endanger satellites in high orbits.
The Americans tried in the early sixties to flood space with tiny metal needles, to increase the return of radio transmissions. Fortunately for them, the Noel project did not succeed and the needles tended to stay grouped together, and luckily so, otherwise we would have just started the space age with Made in America Kessler syndrome. These needles are still a disturbing factor that endangers satellites. I would expect people at the end of the second decade of the 21st century to be a little smarter.
It is possible to place mirror satellites between the sun and the earth that will project the sun's radiation into space
And in this way the weather could also be controlled