The Jovian planets contain most of the matter in the solar system which is not in the Sun

• more massive, but less dense, than the Terrestrial planets

• strong magnetic fields, driven by liquid metallic hydrogen in cores

• accumulated large amounts of hydrogen and helium

• thick, corrosive, high pressure atmospheres, of hydrogen, helium, methane, ammonia, (some evidence for water!)

• no solid surfaces! we see only clouds

• many rings, many satellites

• some of the Jovian planet moons (Europa, Io, Triton) may be likely homes for life!

  Jupiter	Saturn	Uranus	Neptune	Pluto
  Images of the four Jovian planets and of Pluto. [NASA]