earth history, pangea, dinosaur extinction, dinosaur extinction, earth history, documentation, dinosaur documentation, history of the universe, earth documentation, earth history, universe documentation, earth after the dinosaurs, dinosaur documentation, dinosaur extinction, dinosaurs, prehistoric documentation, prehistoric earth, prehistoric animals, science documentation, dinosaur world, before the dinosaurs, before the dinosaurs, after the dinosaurs ------------------------- ???? Earth history: The history of the earth begins with the first seconds of its creation. It has now lasted for almost 4.6 billion years. Marked by mass extinctions, catastrophic events, but also periods of stability, the earth never stops evolving. The mysterious blue planet of the universe is the only one known today to be home to a human form of life. 4.54 billion years ago, the formation of the Earth began with the formation of the Sun. A few million years earlier, our star was formed by the gravitational collapse of a tiny part of a molecular cloud. A disk of gas and dust forms around the young celestial body. These grains slowly clump together until they form small solid bodies, the first fruits of the planets to be formed, the planetesimals. Under the influence of gravity, these planetesimals reach a diameter of up to a few kilometers and eventually form the embryos of planets while freeing the disk of its original dust. The further the orbits are from the Sun, the more massive they become, as they find more material to clump together on their orbit. From a certain distance from the Sun, the planets are able to attract the gases of the hydrogen and helium clouds until they collapse and form the gas giants we know so well: Jupiter and Saturn. Since Uranus and Neptune are smaller, they do not retain the gases, but only their core of rock and ice. The planets that form closer to the Sun are called telluric; they are made of rocks and metals. They are violently impacted when their orbits cross to the point where only four remain: Mars, Venus, Mercury and Earth. All of these planets take 100 million years to form. Theia, a protoplanet, wanders in a stable zone of the cosmos, at the same distance from the Sun as 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 collides violently with the young Earth, which formed 4.52 billion years ago. The impact 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 space. All of these materials orbiting the Earth eventually gather to form the Moon, a satellite about 22,500 kilometers in diameter. The Moon stabilizes the Earth's axis of rotation and slows the same motion through the phenomenon of tidal friction, which explains why a day then lasted only 6 hours and a year 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. It was during this period that Earth's first oceans formed, created by the condensation of water vapor from volcanic outgassing, and possibly supplemented by water delivered by comets. These early oceans were the cradle for the first life forms. Simple single-celled organisms such as bacteria and archaea began to thrive in the primordial soup, laying the foundation for later biological evolution. The Proterozoic Eon, which began about 2.5 billion years ago, saw significant changes in Earth's atmosphere and biosphere. Oxygen levels began to rise due to cyanobacterial photosynthesis, leading to the Great Oxidation Event. This dramatic increase in atmospheric oxygen changed the Earth's environment, allowing the development of more complex, aerobic life forms. It was during this period that the first eukaryotic cells emerged, which eventually gave 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, led to the rapid emergence of most major animal genera. Marine life flourished with the evolution of trilobites, brachiopods, and early fish. In the Ordovician period, life began to colonize the land, and the first plants and fungi appeared. ???? As a reminder, videos are published on Sundays at 6 p.m. This channel is an official affiliate of the ORBINEA STUDIO network