Gal

A Timeline of Earth's History for the First Billion Years

  • 4600 BCE

    Planetary Accretion

    Planetary Accretion
    Planetary accretion occurs as gravitational attraction draws objects together in space. These objects may be dust, gas, plasma (ionized "gas"), debris from comets, etc.
  • 4500 BCE

    Formation of the Moon

    Formation of the Moon
    An asteroid smashed into Earth, which melted most of the Earth and the asteroid itself. These materials was thrown out into orbit. Over time, this material smashed together to form Moon. The moon formed 70 million years after Earth formed.
  • 4430 BCE

    Core Formation

    Core Formation
    A nearby star exploded about 4.5 billion years ago, sent a shock wave through the dust cloud, which increased the rate of spin. Smaller concentrations of mass rotating around the center formed the Earth.
  • 3850 BCE

    End of Heavy Bombardment

    End of Heavy Bombardment
    The end of Heavy Bombardment is a period that highly intensified asteroid impacts taking place between 4.1 to 3.8 billion years ago.
  • 3850 BCE

    Planetary Cooling

    Planetary Cooling
    At first, Earth was molten and lacked an atmosphere and oceans. Gradually, the planet cooled and formed a solid crust. As the planet continued to cool, volcanoes released gases, which eventually formed an atmosphere.