The Earth was formed about 4.5 billion years ago from a cloud of gas and dust in space. This material came together due to gravity, creating a molten mass that eventually cooled and solidified. As the planet formed, heavy elements sank to the center, forming the core, while lighter materials created the crust. Over millions of years, volcanic activity released gases, forming the atmosphere. Water vapor condensed to create oceans, and the planet's surface was shaped by processes like plate tectonics and erosion. These processes continue to shape the Earth today, influencing its landscapes and ecosystems.