MGS Press Conference, 2 October 1997, Figure
Speech given by
This figure shows a cross-section of the planet Mars revealing
an inner, high density core buried deep within the interior. Dipole
magnetic field lines are drawn in blue, showing the global scale
magnetic field that one associates with dynamo generation in the core.
Mars must have one day had such a field, but today it is not evident.
Perhaps the energy source that powered the early dynamo has shut down.
The differentiation of the planet interior - heavy elements like iron
sinking towards the center of the planet - can provide energy as can
the formation of a solid core from the liquid.