The asteroid, which led to the death of dinosaurs, crashed into the Earth with a force, a billion times greater than the power of atomic bombs dropped on Hiroshima and Nagasaki. This is the official point of view. Many believe that this clash led to mass extinction, destroyed dinosaurs on land and many forms of life in the oceans. But there is one nuance that prevents us from knowing for sure how and if this really happened: the Chicxulub crater, left by the asteroid, is buried under a thick layer of sedimentary rocks.
Earlier this year, during an expedition to a place off the coast of Mexico, scientists obtained samples of rocks, having drilled to the solid internal ridges of the crater - known as the “ring of peaks” - at a depth of 1,300 meters below the seabed. The first analysis of these samples has shed new light on how this ring could have been formed.
He also showed how the collision made the rocks of the peak ring more porous. This is important because nutrient-rich porous rocks create good conditions for simple life forms. Therefore, the place of the fall in Chicxulub can show us how other asteroids that had fallen to Earth earlier helped to create the necessary conditions for the development of life. However, there are so many other factors that influenced the origin of life that we need to be careful in the conclusions of one study.
New work under the guidance of Professor Joanna Morgan from Imperial College in London, published in the journal Science, is trying to explain why there is a concentric ring of mountain peaks within the crater. Crater Chicxulub is the only one on Earth that has a ring of peaks. Therefore, the researchers also enlisted the observations of Venus, Mars and the Moon in order to strengthen their theory.
They argue that everything speaks in favor of the so-called “dynamic collapse model” of the formation of a ring of peaks. According to this model, the initial blow pushed the rocks down and then back, after which they came to the surface as a central peak. He then collapsed, pushing rock out of deep bark and overlapping sedimentary layers, thus creating a ring of peaks.
This contrasts with another model, known as the melt cavity model, which is less consistent with the actual data from the Chicxulub crater. In the second model, the central part of the impact crater became so hot that it melted, and this led to the appearance of a ring of peaks using processes that are not fully defined yet.
Data from drilling samples include direct physical evidence of a high level of shock and temperature that affected rocks. These features would not have been possible in the surface rocks of the Earth without extraordinary events like the impact of an asteroid. They are also not part of plate tectonics processes that occur at lower temperatures and pressures than those that could explain the shock of materials.
A new study helps us understand what happened in this area a few minutes after the impact. The sediment layer covering the deeper crust was severely disturbed. In some places on the sedimentary rocks there are rocks from deep bark, which could be there only in the case of a powerful impact and exposure to high energies.
Such strokes play an important role in changing the rocks of the planets or moons, because the bark materials are vertically mixed. Therefore, we can assume that the strikes of asteroids played an important role in the early histories of the planets, including Earth. The new work even briefly mentions that this research could help us understand the processes that led to the emergence of life on our planet.
Morgan notes that by making the rocks of the Earth more porous, asteroids could help create an environment conducive to the development of the first organisms. In particular, these porous rocks could contain nutrients from circulating water that has been heated in the crust.
However, there are large gaps in the explanation of how life could be created using inorganic processes on planetary bodies. The famous experiments of Stanley Miller in the 1950s showed that amino acids could appear during high-energy events (such as a lightning strike) in the presence of carbon dioxide, methane, hydrogen and nitrogen that can be found on the surface of the Earth.
Miller connected a series of glass flasks and allowed four chemicals on them that could be present on the early Earth: boiling water, hydrogen gas, ammonia and methane. He then subjected the gases to repeated electrical effects in order to mimic lightning strikes that were common on Earth at that time.
Miller found that "the water in the bottles became much pinker after the first day, and by the end of the week the solution turned red and muddy." Obviously, a mixture of chemicals formed.
After analyzing the mixture, Miller discovered that there are two amino acids in it: glycine and alanine. Amino acids are often called the building blocks of life. They are used to form proteins that control most of the biochemical processes in our bodies. Miller made the two most important components of life literally from scratch.
The results were published in the prestigious journal Science in 1953. Juri did something very unusual for senior scientists, removing his name from work and giving all the laurels to Miller. Despite this, the study is often referred to as the “Miller – Urey experiment.”
However, since the Earth did not have an ozone shield in its early history that would protect life from ultraviolet light, many came to the conclusion that life was formed in the depths of the ocean. Modern volcanic eruptions at the bottom of the ocean produce emissions that support the mineral communities of organisms and provide a potential alternative place for first life.
In 1977, a group led by Jack Corliss from Oregon State University plunged 2.5 kilometers into the eastern Pacific. They studied the Galapagos hot springs in places where high ridges rose from the seabed. These ridges were volcanically active.
Corliss discovered that these ridges were literally littered with hot springs. Hot, enriched with chemicals water rises from under the seabed and flows through the holes in the rocks.
Incredibly, these hydrothermal springs were densely populated with strange animals. There were huge clams, mussels and annelids. The water was also thickly saturated with bacteria. All of these organisms lived on the energy of hydrothermal vents.
The discovery of these sources made Corliss a name. And it made me think. In 1981, he assumed that such vents existed on Earth four billion years ago and that they became the place of origin of life. He devoted the lion's share of his career to the study of this issue.
Corliss suggested that hydrothermal sources could create chemical cocktails. Every source, he said, was a kind of spray of primary broth.
As hot water flowed through the rocks, heat and pressure caused simple organic compounds to become more complex, such as amino acids, nucleotides, and sugars. Closer to the border with the ocean, where the water was not so hot, they began to connect in chains - to form carbohydrates, proteins and nucleotides like DNA. Then, when the water approached the ocean and cooled even more, these molecules gathered in simple cells.
It was interesting, the theory attracted the attention of people. But Stanley Miller, whose experiment we remembered above, did not believe it. In 1988, he wrote that deep-sea vents were too hot.
Although strong heat can lead to the formation of chemicals like amino acids, Miller’s experiments have shown that it can also destroy them. Basic compounds like sugars "could survive a couple of seconds, not more." Moreover, these simple molecules would hardly be bound in chains, since the surrounding water would instantly tear them apart.
It remains only to find evidence that speaks confidently in favor of one or another theory.
The article is based on materials .
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