Origin of the Solar System

• Big Bang occurred 13.8 billion years ago, after a billion years, galaxies began to form
• 4.571 billion years old is the age of our solar system
• 4.54 billion years old is the age of the Earth based on the age of the meteorites
• 1 Gya ( Gigayears ago ) is equal to 1 billion
• Encounter Hypothesis - a passing star stripped materials from the sun and the hot gases from both started spinning until clumps are form, this also explains why planets are spinning.
• Nebular Hypothesis - a rotating gaseous cloud that cools and contracts in the middle to form the sun and the rest into a disc that become the planets.
• Buffon’s Encounter Hypothesis: Sun-comet encounter that sent matter to form planet;
• James Jean's Encounter Hypothesis: sun-star encounter that would have drawn from the sun matter that

  would condense to planets.
• T.C. Chamberlain and F. R. Moulton’s Encounter Hypothesis : a star much

  bigger than the Sun passing by the Sun and draws gaseous filaments from both out which planetesimals were formed.
• Ray Lyttleton’s Encounter Hypothesis : Sun’s companion star colliding with another to form a proto-planet

  that breaks up to form Jupiter and Saturn.
• Protoplanet Hypotheses - a slowly-rotating gas and dust cloud starts to contract due to gravity, as most of the mass move to the center to eventually become a proto-Sun, the remaining materials form a disc that will eventually become the planets.