The Earth formed about **4.5 billion years ago** from a rotating disk of gas and dust surrounding the young Sun. This process began when gravity pulled together particles to form small planetesimals, which collided and merged to form larger bodies, eventually coalescing into planets. Earth's early surface was molten due to intense heat from collisions, radioactive decay, and the compression of materials. Over time, it cooled, forming a solid crust.

During Earth's early development, a Mars-sized body collided with the young planet, ejecting material that eventually formed the **Moon**. The impact also contributed to Earth's tilt, which creates the seasons.

As the Earth continued to cool, volcanic activity released gases, forming the **early atmosphere**. Water vapor condensed into oceans as the surface temperatures dropped. This set the stage for the appearance of life. The planet’s conditions stabilized, allowing for the formation of the continents, oceans, and atmosphere we recognize today.