Physical Geography

  1. The Earth is a part of the Solar System, which includes the Sun, eight planets, and other celestial bodies.
  2. The Big Bang Theory explains the origin of the universe approximately 13.8 billion years ago.
  3. The Solar System is believed to have formed about 4.6 billion years ago.
  4. The nebular hypothesis proposed by Immanuel Kant and Pierre-Simon Laplace suggests the Solar System formed from a rotating cloud of gas and dust.
  5. The protostar at the center of the nebula eventually b