Four Major Characteristics of the Solar System

  1. Large bodies in the solar system have orderly motions
  2. Planets fall into two main categories:
  3. Swarms of asteroids and comets populate the solar system.
  4. Several notable exceptions to the general trends:

Terrestrial vs Jovian

Terrestrial planets Jovian planets
Mercury, Venus, Earth, Mars Jupiter, Saturn, Uranus, Neptune
smaller size and mass larger size and mass
solid surface no solid surface
higher density (rocks, metals) lower density (light gases, hydrogen compounds)
metallic core and a rocky outer layer rocky core which resembles the terrestrial planets
orbits closely spaced orbits spaced far apart
few (if any) moons, no rings many moons, rings
warmer cooler


Definition of planet

Size comparison

Mass and Density

Age of the Solar System

The age of our solar system has been established to be about 4.6 billions years, based on the following pieces of evidence:



Extra-solar systems

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