Primary Connections: Linking science with literacy

Primary Connections: Linking science with literacy
© State of Victoria (Department of Education, Employment and Training)

The outer planets

The outer giant gaseous or Jovian planets: Jupiter, Saturn, Uranus and Neptune, are much more massive than the inner, terrestrial, planets and have immense atmospheres composed mainly of hydrogen (H) and helium (He). They have no solid surfaces and their densities, averaging less than 2 g/cm³, are so low that if Saturn could fit in an ocean, it would float on the water. Each of the outer planets has a magnetic field, a ring system, and many satellites.

Pluto is unique in that it is an icy, low-density body smaller than the Earth's Moon, resembling a giant comet nucleus or an icy satellite of one of the outer planets. Pluto has no rings and only a single satellite.