Solar system and stars

• Solar system

  The sun is at the centre, with planets orbiting the sun
• Objects in the solar system

  • Sun
  • Planets
  • Asteroids
  • Comets
• Asteroids

  • Small rocky objects that orbit the sun, too small to be considered planets
• Comets

  • Formed from ice and dust, orbit the sun in elliptical paths
• Astronomical unit (AU)

  Mean distance measurement from the sun to the planets
• Distance from the sun increases

  Lightyears travel time increases
• Distance from the sun increases

  Temperature decreases
• Formation of the solar system

  1. Cloud of gas and dust from a supernova

  2. Cloud spins and condenses

  3. the centre becomes the sun

  4. Outer edge becomes the planets
• Inner planets


  • Rocky planets due to their distance from the sun
• Outer planets


  • Gaseous planets due to their distance from the sun
• Elements were pushed further out due to the gaseous nature of the early solar system
• Life cycle of stars

  1. Formed from clouds of gas

  2. Gravity compresses the gas

  3. Hydrogen fuses to form helium in main sequence

  4. Hydrogen begins to run out, star expands to red giant

  5. Helium fuses to form heavier elements

  6. Star sheds outer layers, leaving behind a white dwarf or for a large mass star, a neuron star or black hole
• Stages of high mass stars evolution

  • Protostar
  • Main sequence
  • Red giant
  • Supernova
  • Neutron star
  • Black hole