models of the solar system

• Astronomers nowadays


  • Use spacecrafts and very powerful telescopes to explore and observe the Solar System
• Early astronomers


  • Could only use their eyes to investigate the Solar System
• Planets visible to the naked eye

  • Mercury
  • Venus
  • Earth
  • Mars
  • Saturn
• Geocentric Model


  The Earth is at the centre of the Solar System, with the Moon, Sun and planets moving in circles around the Earth
• Ptolemy proposed the Geocentric Model

  2nd century
• Geocentric Model was the accepted model


  1500 years
• Heliocentric Model


  The Earth and other planets move around the Sun
• Nicolas Copernicus suggested the Heliocentric Model


  1543
• The Heliocentric Model was supported by the observations of Galileo Galilei
• Galileo Galilei


  • One of the first astronomers to use a telescope to view space
  • Able to make more accurate measurements and observations
  • Supported Nicolas Copernicus' Heliocentric Model
• Current Model of the Solar System

  The Sun is in the centre of the Solar System, and the planets move around the Sun in elliptical orbits
• Most planets have natural satellites called moons which orbit them
• Spacecrafts


  • Nowadays, we can explore space using spacecrafts
  • Luna 2 was the first spacecraft to reach the Moon in 1959
  • Before spacecrafts, astronomers could only investigate space using telescopes
  • Voyager 1 was launched in 1977 and is now over 19 billion kilometres away