Chapter IV
Overview of the Planets in Our Solar System.........................................................
Earth
Fig. 4.3 Earth Field
Planet earth is a blue planet with a moderately humid climate and a lightly unstable sur-
face, 70% of which is covered by water. Its atmosphere consists mainly of nitrogen and
oxygen. Under the 32km (approximately) thick earth crust we find a 3000 km thick inner
mantle. The core of the earth is a moving sea of liquid nickel and iron, which creates a
strong electromagnetic field. It rotates around its axis in one day and around the sun in
one year.