The History of Earth

  • 4600 BCE

    Birth of Sun

    Birth of Sun
    In the beginning, the solar system started as a gas cloud that moved around the galaxy. At some point, a star nearby exploded and sent a shock wave through it. This caused the gas cloud to gravitationally collapse, forming the sun and a protoplanetary disk around it.
    Source: Video #1
  • 4510 BCE

    Formation of Moon

    Formation of Moon
    Theia, a planetoid the size of Mars, crashed into the Earth and knocked some debris off of it. The debris orbited the earth and eventually coalesced into the moon.
    Source: Video #4
  • 4500 BCE

    Primary Accretion Stage

    Primary Accretion Stage
    During the primary accretion stage, the dust was colliding into each other and creating little clumps.
    Source: Video #1
  • 4400 BCE

    Planetary Cooling

    Planetary Cooling
    The force of the moon-forming impact left Earth a churning hot magma blob. But as the planet cooled, lava became rock and liquid water started to condense, forming Earth's first ocean. Source: Photo Timeline
  • 3800 BCE

    End of Heavy Bombardment

    End of Heavy Bombardment
    A lot of violence occurred that Jupiter and Saturn migrated their ways towards the inner planets, sent rocks raining down on the inner planets, and eventually migrated back out. During that stage, comets carrying water hit the earth, explaining the existence of water on earth.
    Source: Video #1
  • 3500 BCE

    Generation of Oxygen

    Generation of Oxygen
    The first whiffs of oxygen — from the evolution of photosynthesis — emerged in rocks about 3.5 billion years ago.
    Source: Photo Timeline
  • 1500 BCE

    Earth's Core Formation

    Earth's Core Formation
    Radiations from the recent supernova and all of the collisions caused Earth to become so hot that the rock and metal began melting. Heavier materials sank to the bottom and lighter elements rose to the top. This transformation created the earth’s core.
    Source: Reading #1 & Video #3