The Origin of the Earth

The Planets of the Solar System

Most of our knowledge of planetary evolution is drawn from the study of the solar system. A wealth of helpful descriptive data about our solar system can be found at http://www.hawastsoc.org/solar/eng/solarsys.htm. A similar site with a huge amount of detail is http://www.ex.ac.uk/Mirrors/nineplanets/.

Some of the more important points are summarised in the table below:

    The Terrestrial Planets The Jovian planets  
Body Sun Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune Pluto
Distance1 0 0.39 0.72 1 1.15 5.2 9.2 19.2 30.1 39.5
Density2 1.41 5.43 5.25 5.52 3.95 1.33 0.69 1.29 1.64 2.03
Radius3 109 0.38 0.95 1 0.53 11 9 4 4 0.18
  1. Increasing Mean distance from Sun (Earth to Sun = 1.0)
  2. Mean density of terrestrial planets greater than that of Jovian planets
  3. Radius of terrestrial planets less than that of Jovian planets (Earth = 1.0)