- 3201 - EARTH’S - core and how life began? We may never know exactly what led to the appearance of life on Earth. But we can at least build a trail of evidence that leads to the necessities for it to appear. The creation of some of the chemicals necessary for life might be more common than originally thought.
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- Despite being quite close to us, the Earth’s core is still a mysterious place. We can divide it into the inner core and the outer core. We also know it’s mostly composed of iron, and it’s responsible for the magnetic field of our planet.
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- The Earth’s structure is quite similar to an onion. It is made of at least four layers. Each layer has a different structure and plays a different role in the Earth’s geology. Two of the layers of Earth create the core.
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- The outer core lies about 3,000 kilometers from the surface, and it is the only liquid layer of the Earth. That is because it’s not under enough pressure to be solid. It is made mostly of iron, nickel, with sulfur and oxygen.
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- The temperature inside is extremely high- up to 6,000°C (10,832 °F). Due to the convection of fluid ferromagnetic substances, the Earth creates a magnetic field. This, in turn, leads to a stable atmosphere and conditions for life.
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- The innermost layers of the Earth comprise the inner core. It is probably a solid sphere with about a 1,200 kilometers radius (70% of the Moon’s radius), and it is as hot as the surface of the Sun (about 5,600°C).
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- Quite like the outer layer, it is made of iron and nickel. The inner core has two layers.
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- The data collected in 2015 showed that the crystals in the inner layer are in an east-to-west direction. Those in the outer line up north to south. This implies a phenomenon that flipped the core’s orientation, turning the crystals in the ‘outer’ inner core.
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- In our planet’s core the moving iron and nickel create a magnetic field. That magnetic field protects the layer from the solar wind and UV radiation. Therefore, it protects life on our planet from harmful particles.
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- The core’s radiating heat keeps the Earth’s surface warm. Sometimes people use that geothermal energy to warm their houses. This is done in Iceland.
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- Earth’s layers are just a few kilometers down from us, but , we know more about the Moon than our own planet’s interior.
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- The deepest human-made core, the Kola Superdeep Borehole, reaches only 12.2 kilometers into our planet. That’s not even halfway through the lithosphere which is the outermost layer!
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- All studies of the Earth’s inner and outer core come from seismic data. Another unknown is the periodic reversals of the Earth’s magnetic field.
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- Even though scientists estimated the temperatures, there is no way to go directly down to the core because of both the temperature and the pressure.
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- In the 1940s, scientists calculated the original balance of minerals on Earth and concluded that the missing iron and nickel must be in the core.
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- However, only 10 years later, the gravity measurements proved them wrong. The core must be heavier and denser than originally thought, though we don’t know which elements occur inside.
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- The asteroid “Psyche” might be a naked iron core floating in space. The “2022 Psyche Mission” may give us some answers on the structure of the Earth’s core. Moreover, it will help us compare other solid planets’ iron cores and show their most common properties.
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- After knowing what the Earth is made of there is an even greater question: How did life begin on Earth? Did the heat from asteroid impacts help life get started?
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- The focus is on asteroids impacting Earth and delivering water and chemicals. It is possible that the heat from those impacts generated water and life-origin chemicals on the asteroid’s surface, then delivered them to Earth.
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- An earlier Earth would not have liquid water on its surface because it would hsve boile away.
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- A laboratory asteroid proxy was made of porous gypsum. They placed thermocouples inside this asteroid moel to measure heat. Then they created high-velocity impacts by accelerating projectiles with a gas gun.
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- “Aqueous alteration” is when minerals in rock change because of chemical reactions with water. Those reactions can create organic solids.
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- But for those reactions to take place, there must be heat to melt the asteroid’s ice. In larger bodies, scientists think that the decay of Aluminum 26, a radioactive isotope, can provide this needed heat for aqueous alteration.
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- But that only occurs in larger asteroids of about 10 kilometers in diameter and may only have occurred in the Solar System’s first 10 million years or so before all of the Al 26 had decayed.
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- Could aqueous alteration have occurred due to impacts on smaller asteroids much later into the Solar System’s life?
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- The scientists monitored the temperature created by the impacts as they raised the velocity of their projectiles. They wanted to know not only how much heat was generated but how long that heat would persist. Could asteroid impacts create enough heat to create life-origin chemicals without destroying the asteroids themselves?
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- How widespread are these conditions in the Solar System, and could these chemicals still be generated in older Solar Systems like ours?
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- In the main asteroid belt the relative velocity among asteroids is about 4 to 5 kilometers / second. The shock of these collisions would have immediately raised the temperature around the resulting crater. Collisions like these were common in our Solar System’s youth, long after all of the Al 26 had decayed.
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- The heat from these impacts would have been most pronounced on more porous asteroid bodies. The researchers used different types of projectiles traveling at different velocities to develop a model of impact heating.
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- The researchers found that the potential for asteroid impacts to create chemicals necessary for life is more widespread than previously thought. It’s more widespread both spatially and temporally, and the necessary heat can be created from impacts that create craters as small as 100 meters in diameter.
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- These results increase the number of astronomical bodies that could have delivered water and organic substances for the origin of life on Earth.
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- Another interesting result of their work involves organic solids that originated in the nebular cloud at the very beginning of our Solar System’s formation. This research showed that the heat from impacts may be like a double-edged sword. Not only can that heat forge new organic materials, but it can destroy the same type of materials present on asteroids and asteroid parent bodies since the early days.----- See other reviews:
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- 3105 -- EARTH - finely tuned for life? How did it get that way? Are we here as a result of random collusions and mutations? We only know life that is us. That is a sample size of one. Regardless, Earth's history demonstrates that life can take root and evolve. Here is what we have learned.
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- 3068 - EARTH - magnetic field flips N. to S.? - The end of the world as we know it could come in any number of ways. Some believe global cataclysm will occur when Earth's magnetic poles reverse. When north goes south, the continents will lurch in one direction or the other, triggering massive earthquakes, rapid climate change and species extinctions. We are a species too.
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- 3055 - EARTH - magnetic pole shift. The temporary breakdown of Earth's magnetic field 42,000 years ago sparked major climate shifts that led to global environmental change and mass extinctions. The Earth suffered electrical storms, widespread auroras, and cosmic radiation, all triggered by the reversal of Earth's magnetic poles.
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- 3040 - EARTH - evolution of the Solar System? - To carry our lineage back further this review is about the geological history of our Solar System. We do not have many rocks to work with, a few meteorites, so the history lesson takes more imagination. By studying the rocks, gas , and stars within 6,500 lightyears of Earth with detailed observations.
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- 2970 - EARTH - unusual places? Our Earth is a dynamic planet, and there is much about its history and ongoing processes on land, in the oceans and deep under the surface that scientists are still discovering. Here are several examples that should interest you:
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- 2927 - EARTH - Revolutions and orbits are how we tell time. We not only know that Earth’s orbit slightly changes over time, but we can quantify and confidently state exactly what those changes will be. What does this mean for the speed of Earth around the Sun? Are years getting longer or shorter?
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- 2903 - PREHISTORIC EARTH - how did life get started? Four billion years ago, Earth was covered in a watery sludge swarming with primordial molecules, gases, and minerals, nothing that biologists would recognize as alive. Out of that prebiotic stew emerged the first critical building blocks, proteins, sugars, amino acids, cell walls, that would combine over the next billion years to form the first specks of life on the planet.
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- 2875 - EARTH - climate change got us here? A coupled increase in atmospheric CO2 and decrease in surface ocean pH, global warming, changes in productivity and oxygen depletion have been reported worldwide, which suggests that the scenario outlined here may be relevant to understanding future environmental and climatic trends.
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- 2869 - EARTH - waster, water everywhere? There remains a number of mysteries on our planet including the elusive origin of the blue water on the Earth. Scientists have found the interstellar organic matter could produce an abundant supply of water by heating, suggesting that “organic matter” could be the source of terrestrial water.
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- 2486 - EARTH - Third Rock from the Sun. The Sun’s energy itself is changing in its light energy. It has several cycles of its own , “Could Our Sun Be a Variable Star?” . Today we are considered to be in a normal warming trend. Global warming is claimed to be exacerbating this warming trend with human burning of fossil fuels and putting greenhouse gases into the atmosphere.
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- June 27, 2021 EARTH’S - core and how life began? 3201
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--------------------- --- Sunday, June 27, 2021 ---------------------------
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