Earth's Early History (1 year = 1 mil years)

  • 4567 BCE

    Planetary Accretion

    The Earth was formed around 4.567 billion years ago. It was small when compared to the Sun and the other celestial bodies in the solar system ​but gradually acquired mass over time.
  • 4500 BCE

    Formation of Outer Core

    The process of forming the Earth's different layers took over 10 million years, but the formation of its outer core completed around 4500 years ago.
  • 4470 BCE

    Formation of the Moon

    The moon was formed around 4.5 billion years ago. It was created when debris, from a ​massive collision between a smaller proto-Earth and another planetoid, went into orbit.
  • 4100 BCE

    Planetary Cooling

    About 4.1 billion years ago, the Earth's surface began to cool, thus creating the solid surface of its rocky terrain.
  • 3800 BCE

    End of Heavy Bombardment

    The end of the heavy bombardment was around 3.8 billion years ago. This was when the asteroids stopped impacting Earth and its surrounding terrestrial planets.