history of the earth,documentary,documentary on dinosaurs,history of the universe,documentary on the earth,history of the earth,documentary on the universe,the earth after the dinosaurs,documentary on dinosaurs,extinction of dinosaurs,dinosaurs,prehistoric documentary,prehistoric earth,prehistoric animals,scientific documentary,dinosaur world,before the dinosaurs,before the dinosaurs,after the dinosaurs ???? The history of the Earth: The history of the Earth begins from the first seconds of its formation. It has been going on for almost 4.6 billion years now. Marked by mass extinctions, catastrophic episodes but also periods of stability, the Earth continues to evolve. A mysterious blue planet in the universe, it is the only one known today to harbor a form of human life. 4.54 billion years ago, the accretion of the Earth began with the formation of the Sun. A few million years ago, the gravitational collapse of a tiny part of a molecular cloud caused our star to appear. A disk of gas and dust formed around the young celestial body. These grains slowly clumped together until they formed small solid bodies, the beginnings of future planets, the planetesimals. Under the effect of gravity, these planetesimals reached up to a few kilometers in diameter, eventually forming embryonic planets while ridding the disk of its original dust. The further the orbits are from the Sun, the more massive they are because they find more matter to clump together along their trajectory. After a certain distance from the Sun, the planets are able to attract gases from the clouds composed of hydrogen and helium until they collapse on themselves, giving birth to the gas giants that we know well: Jupiter and Saturn. Uranus and Neptune being smaller, they do not retain gases but only their core of rock and ice. The planets that form closer to the Sun are called telluric, they are composed of rocks and metals. They are violently struck when their orbits cross to the point that only four remain: Mars, Venus, Mercury and Earth. The formation of all these planets lasts 100 million years. Theia, a protoplanet, wanders in a stable zone of the cosmos, at the same distance from the Sun as the Earth. When it reaches the size of Mars, Theia is destabilized by the gravitational influence of the other planets. Its orbit becomes chaotic and it violently collides with the young Earth forming 4.52 billion years ago. The shock is so violent that Theia's iron core plunges into the heart of the Earth. The rest of the planet and part of the Earth's mantle are ejected into the cosmos. All of this material orbiting the Earth eventually comes together to form the 22,500-kilometer-long moon, the Moon. The Moon stabilizes the Earth's rotation axis and slows down the same motion through tidal friction, which explains why at that time a day lasted only 6 hours and a year 1,434 days. When the Earth began to cool, a solid crust formed, marking the beginning of the Archean eon, about 4 billion years ago. It was at this time that the Earth's first oceans appeared, created by the condensation of water vapor from volcanic outgassing and perhaps supplemented by water brought by comets. These early oceans were the cradle of the first forms of life. Simple single-celled organisms, such as bacteria and archaea, began to thrive in the primeval soup, setting the stage for the biological evolution that would follow. The Proterozoic Era, which began about 2.5 billion years ago, was marked by significant changes in Earth's atmosphere and biosphere. Oxygen levels began to rise due to photosynthesis by cyanobacteria, leading to the Great Oxidation Event. This dramatic increase in atmospheric oxygen transformed Earth's environment and allowed for the evolution of more complex aerobic life forms. It was during this time that the first eukaryotic cells appeared, which would give rise to multicellular organisms. The Paleozoic Era, which began about 541 million years ago, marked a period of profound diversification of life forms. The Cambrian Explosion, a relatively short period, saw the rapid emergence of most major animal groups. Marine life flourished, with the development of trilobites, brachiopods, and the first fish. In the Ordovician, life began to colonize the land, with the appearance of the first plants and the first fungi.