A new study seems to indicate that Mars has a completely molten core. The conclusion was reached by creating the temperature and pressure thought to be found there on a model of the core. This finding matches well with other observations, such as how easily the sun is able to distort the planet's shape. The finding supplies a neat explanation as to why Mars's magnetic field turned off so long ago while the Earth's keeps going strong. It also predicts that some day Mars's magnetic field could turn itself back on.