Direct Observations
, Evidence to Support the Earth’s Composition
• We can find out about distant planets and moons more easily that
we can find out about the composition of the Earth’s interior. First-
hand observation and sampling of rocks and structures allow us to
touch rocks from a maximum depth of just 250km.
• As it is 6,371km to the centre of the Earth, the only part of the Earth
that can be observed directly is the top 3.7%.