Solved riddles of the Mars magnetic field?

Marsian mystery: Our neighboring planet Mars has no fixed inner core – so it lacks the crucial component for a magnet dynamo. But how could young Mars then generate its magnetic field? Planetary scientists could have solved this riddle. Their model also explains why today we only find magnetic field remnants in the southern hemisphere of Mars and what the Mars magnetic field, which existed until about 3.7 billion years ago, looked like. The Eart…