The Real Story Of The Formation Of Earth

 


Have you ever how the earth was formed and everything cam to existences? So, today in this blog i have the full coverage story for you on how the earth was formed.

As far as scientists know, Earth is the only living planet in the galaxy. Born 4.6 billion years ago from a cloud of cosmic dust and gas, our 7,917.5-mile-diameter ball of rock is home to nearly 9 million different species – and has hosted many more millions since life began. The amount our planet has achieved over its relatively short life span is astonishing. But its journey from a lifeless rock to a paradise island in the cosmos hasn’t been easy. Earth wasn’t one of the first planets in the universe – in fact, it’s relatively young. Our Sun is a second-generation star, one of a group called Population I. It was born out of the remnants of much older stars after they ran out of fuel. When the universe began 13.8 billion years ago, the only elements were hydrogen and helium. These lightweight gases formed the first bright, hot stars. Some of these stars had gas planets, but they didn’t have rock or metal – as they didn’t exist yet – and without those, life was impossible. The elements life needed were forged inside those early stars. The heat and pressure within squashed the lightweight gases together to form the first 26 elements in the periodic table, up to and including iron. These are the elements that now make up the bulk of planet Earth, and its many inhabitants. When those first stars ran out of fuel, they stopped fusing elements and started to collapse. Some became so unstable that they exploded. The blasts were so violent that they created even heavier elements, like gold and radioactive uranium, before showering the contents of the dying stars into space. After the dust of the explosions settled, all that was left were clouds called nebulae. It was from one of these clouds that the Solar System emerged. Earth, and everything on it, is literally made of stardust. Most of the rock that makes up the outer surface of our planet was forged in the first stars of the universe. These elements include oxygen, silicon, aluminium, iron, calcium, sodium, potassium and magnesium. Underground in the flowing rock of the mantle are more stellar elements – silicon, magnesium and iron – and right at the centre, in the liquid core, is a mixture of molten iron and a supernova element, nickel. In its earliest days, Earth was just a hot rock in a lifeless star system. But the star forged elements it contained gave it the power to become so much more. Ancient hydrogen combined with oxygen to make rain, coating the planet in vast oceans. Those oceans dissolved minerals from the first stars, becoming a salty chemical soup. Violent weather, volcanic activity and radiation from the Sun provided the heat and sparks to jolt that soup into life, and that changed our planet forever. Every living organism on Earth is made of recycled stars, and most of them contain supernova dust, too. Inside your own body, iron allows your blood cells to carry oxygen, zinc enables your immune system to fight infection and selenium makes antioxidants that shield your cells from damage. The journey from cloud of dust to living planet has been a long one, but here we’ll cover just how our lively planet evolved.
Solar System Formation

The Solar System was born from a cloud of dust called a nebula. A shock wave, triggered by the death of a nearby star, caused that nebula to collapse. It tumbled in on itself, forming a hot, white ball of matter that became so dense that atoms at its core started to fuse. These nuclear reactions gave birth to the Sun. Around that young star, the rest of the cosmic dust from the nebula continued to swirl. It formed small clumps that started to grow by a process called accretion. These clumps became the planets and moons. The formation of the planets took millions of years, and it wasn’t peaceful. As Earth was beginning to take shape, large chunks of rock and ice were still hurtling through the Solar System. They would crash into Earth at random, melting the ground and sending violent shock waves into the mantle. The biggest of these collisions was with a planet-sized rock called Theia, which formed our Moon. Though devastating, that encounter played a vital role in the evolution of our planet. It stabilised Earth’s rotation, helping to steady the climate, and it created the tides. By the time Earth started to cool, most of its water had boiled away into space, and in the early years it didn’t even have an atmosphere. Luckily, another planet was on hand to help. Jupiter sits just beyond the asteroid belt. Its massive gravitational influence slows passing rock fragments, pulling them into orbit around the Sun. It acts as our protector, but also as a slingshot, sending some of those asteroids and comets right into our path. The projectiles Jupiter hurled at our planet in the early years of the Solar System were full of hydrogen and oxygen, the raw ingredients of water. These elements melted into the mantle and came out as rain when ancient volcanoes erupted, turning the bare rocks of early Earth into mineral-rich oceans.
The Forming Of The Earth

Just after the birth of the Solar System, in the Hadean Eon, the entire Earth was liquid, a hellscape of fire and lava. The planet was still being pummelled from all directions by meteor strikes. As Earth started to cool, a crust of solid rock began to appear on its surface, but at first it was very fragile. Repeated impacts and volcanic eruptions broke that crust into chunks called tectonic plates, which floated on the magma below. During the Archaean Eon, 4 to 2.6 billion years ago, the plates started moving, but when they collided, the heat of the mantle would break them apart. They had to stop, cool down and recover before they could start moving again. By the time this eon came to an end, tectonic plates had become more stable, and they had started to move constantly. Across history the plates have continually collided and separated, forming and reforming different patterns of continents and oceans.
Earth climate

These movements have had dramatic effects on Earth’s climate. When continents break apart, the exposed rock absorbs carbon dioxide from the air, and global temperatures plummet. As volcanoes erupt, the greenhouse gases break free again and blow back into the atmosphere, trapping heat from the Sun. Events like these have triggered enormous freeze-thaw cycles in Earth’s past. Earth’s position in space has influenced global climate too. After its collision with Theia, Earth’s axis fell into a tilt, creating the seasons. That tilt has always been unstable, and so has the shape of Earth’s orbit around the Sun. Our distance from the Sun changes on a 100,000-year cycle, tipping us in and out of ice ages. For the first part of Earth’s existence, its climate was entirely dominated by these quirks of space and geology, but when life evolved everything changed. During the Proterozoic Eon, evolution invented photosynthesis. The atmosphere filled with oxygen and gained a protective shield called the ozone, making it possible for living organisms to start terraforming the land. Our impact on the climate has been monumental, and today humanity is one of the most powerful forces of climate change.
Formation Of Atmosphere

Earth lost all its air almost as soon as it formed. Most of the gas was hydrogen and helium, and Earth’s gravity simply wasn’t strong enough to hold it down. This meant that in the earliest days, there was no air at all. Earth’s first atmosphere emerged from the belly of the planet. Gases bubbled up to the surface during violent volcanic eruptions, covering the ground in a hot blanket of carbon dioxide, nitrogen and water. Then came the rain. The water leaked out of the atmosphere in torrents that formed the first oceans, leaving nitrogen as the dominant atmospheric gas. When life eventually evolved, the atmosphere changed again. Photosynthesising organisms pulled carbon dioxide from the air and split it apart, turning the carbon into food for their bodies and spitting the oxygen back out as waste. As that oxygen started to build up, ultraviolet light from the Sun shattered it into pieces. Those pieces recombined to make the ozone layer
The Origin Of Life


Life on Earth is like nothing else in the universe – at least that we know of. Our planet is home to an estimated 8.7 billion different species. The smallest is the 400-nanometre microbe Nanoarchaeum equitans; the largest the six-mile honey fungus. Both of them, and everything in between, can trace their evolutionary ancestry back to a single species, known as the last universal common ancestor, or LUCA. LUCA was a single cell with a little loop of genetic code carrying 100 essential genes, which it passed on to almost every organism alive today. A microbe, it lived 3.5 billion years ago in a hot volcanic vent deep beneath the surface of the ocean. There was no oxygen to breathe at the time, so LUCA survived on hydrogen, carbon dioxide and nitrogen. It made its energy using the natural gradient of ions that exists between hot thermal vent water and cold seawater. LUCA gave rise to all three branches of the tree of life: the archaea, the bacteria and the eukarya. Each branch has left its mark on Earth, changing everything from the composition of the atmosphere to the shape of the land, the climate and the weather. The archaea are the oldest and perhaps the strangest of Earth’s organisms. They live in places no other life can survive, like boiling vents, bubbling acid and frozen ice. The bacteria are the smallest and most prolific. The eukarya are the youngest and most diverse of Earth’s creatures. They include almost all life you see around you, from plants and animals to fungi, yeast and amoebae. LUCA was the shared ancestor of everything, but it wasn’t Earth’s first life form. Fossil evidence of life on Earth dates back as far as 3.7 billion years, and scientists believe that the first living organisms emerged even earlier. The very first living organism had to come from something not living, a process that scientists call abiogenesis. But how that happened is still a mystery. What we do know is that life began when Earth was in its Hadean Eon, a time when rust was raining down on the planet. Violent iron hailstorms tore through the atmosphere, reacting with water to form red dust. This reaction produced hydrogen as a waste product, and that hydrogen was key to the formation of life. It had the power to reduce other chemicals, adding electrons and stripping away oxygen. These reduction reactions created the three building blocks of life: nucleic acids, fatty acids and amino acids. Alone these building blocks are not alive, but when they combine, something incredible happens. Strings of nucleic acids form RNA and DNA, the carrier molecules of genetic code. Strings of amino acids form proteins, the molecular machines that drive the chemistry of living organisms. And fatty acids form bubbles called membranes, which separate life from the rest of the world. Scientists disagree about which of these molecules came first, but it was the combination of the three that made life on Earth possible.
Where Did The Cells Come From

One of the biggest events in the history of evolution was the development of mitochondria, the energy factories of all complex cells. Scientists think that they only evolved once, an event that completely changed the course of evolution. For billions of years, life was just single cells. It was impossible to make enough energy to form multicellular organisms like plants and animals. When oxygen appeared in the atmosphere, some cells learned how to use the new gas. In a chance event, one of these oxygen-breathing cells got inside a larger cell and started dividing. The two types of cell started to work together to make more energy than ever before. Over time, their relationship became permanent, and the oxygen-breathing cells became the mitochondria.
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