history of the earth, pangea, dinosaur extinction, dinosaur extinction, history of the earth, documentary, dinosaur documentary, history of the universe, documentary about the earth, history of the earth, documentary about the universe, earth after the dinosaurs, documentary about dinosaurs, dinosaur extinction, dinosaurs, documentary about prehistory, prehistoric earth, prehistoric animals, documentary about science, world of dinosaurs, before the dinosaurs, before the dinosaurs, after the dinosaurs ------------------------- ???? History of the Earth: The history of the Earth begins from the first seconds of its formation. It has now been taking place for almost 4.6 billion years. Marked by mass extinctions, catastrophic episodes but also periods of stability, the Earth never stops evolving. Mysterious blue planet in the universe, it is the only one known today to host 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 earlier, the gravitational collapse of a small 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 clustered together to form small solid bodies, the first fruits of the planets in the process of formation, the planetesimals. Under the effect of gravity, these planetesimals reached a diameter of several kilometers, eventually forming embryos of planets and clearing the disk of original dust. The further their orbits are from the Sun, the more massive they are because they find more material to agglomerate along their path. After a certain distance from the Sun, the planets are able to attract the gases from the clouds made of hydrogen and helium until they collapse on themselves, giving rise to the gas giants we know well: Jupiter and Saturn. Since Uranus and Neptune are smaller, they do not retain gases but only their core of rock and ice. The planets that form closest to the Sun are called telluric planets, made of rocks and metals. They are violently impacted when their orbits cross so much 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 area of ​​the cosmos, at the same distance as Earth from the Sun. 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, which was forming 4.52 billion years ago. The impact is so violent that Theia's iron core falls into the heart of the Earth. The rest of the planet and part of the Earth's mantle are ejected into the cosmos. All this material in orbit around the Earth eventually comes together and gives rise to the satellite that is the Moon, about 22,500 kilometers away. The Moon stabilizes the Earth's rotation axis and slows this motion thanks to the phenomenon of tidal friction, which explains why a day lasts only 6 hours and a year has 1,434 days. As the Earth began to cool, a solid crust formed, marking the beginning of the Archean Eon, about 4 billion years ago. During this time, Earth's first oceans appeared, created by the condensation of water vapor from volcanic degassing and perhaps supplemented by water transported by comets. These early oceans were the cradle of the first life forms. Simple single-celled organisms, such as bacteria and archaea, began to thrive in the primordial soup, laying the foundation for the biological evolution that would follow. The Proterozoic Eon, starting about 2.5 billion years ago, saw significant changes in the Earth's atmosphere and biosphere. Oxygen levels began to increase thanks to the photosynthesis of cyanobacteria, giving rise to the Great Oxidation Event. This dramatic increase in atmospheric oxygen transformed the Earth's environment and allowed the evolution of more complex aerobic life forms. The first eukaryotic cells appeared during this period, which would later 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 of time, saw the rapid emergence of most of the major animal phyla. Marine life flourished, with the development of trilobites, brachiopods, and the first fish. In the Ordovician Period, life began to colonize land, with the appearance of the first plants and fungi. ???? As a reminder, videos are published on SUNDAY at 6:00 PM. This channel is an official affiliate of the ORBINEA STUDIO network. This channel is an official affiliate of the ORBINEA STUDIO network.