Of The Earth: The History

Earth formed from the , a swirling disk of dust and gas leftover from the sun's birth. For millions of years, gravity pulled rocks together, creating a molten, white-hot sphere. During this "Hadean" period, a Mars-sized object named Theia slammed into Earth; the debris from this collision eventually coalesced to form the Moon .

As the planet cooled, a solid crust formed. Steam from volcanic eruptions and ice-carrying comets condensed into the first . In these chemical-rich waters, the miracle happened: the first microscopic life appeared. Eventually, organisms called cyanobacteria evolved photosynthesis, pumping oxygen into the atmosphere for the first time—an event known as the Great Oxidation Event . 3. The Age of Complexity (541 – 66 Million Years Ago) The History of the Earth

Life exploded in complexity during the . Creatures moved from the sea to the land, leading to the age of lush forests and massive insects. This era saw the rise and fall of the Supercontinent Pangea and the reign of the Dinosaurs . For 165 million years, these giants dominated the planet until a massive asteroid struck the Yucatan Peninsula, triggering a mass extinction. Earth formed from the , a swirling disk