Without a circulating magnetic fluid between the planet s solid core and mantle, a strong magnetic field will never develop. Without a magnetic field, the planet has no shield to guard it from the sun s x-ray radiation. This discovery about Mars s lack of such shielding certainly impacts any plans for a manned mission to Mars. The dangers, already known to be grave, now seem graver by far. At the same time, this new understanding about the intricacies of magnetic field formation reveals another wonder of Earth.
Life can exist on Earth because Earth has a strong, stable magnetic field.
This field s strength and stability are determined, in part, by the abundance of sulfur in Earth s core. Acuna, et al , p. 1679.