Two different models of solar magnetic field lines

One of the major discoveries of Ulysses concerns the understanding of the solar magnetic field and how solar particles are transported along it. Before Ulysses, the field lines were thought to expand as ordered ‘garden hose’ spirals (left panel). Ulysses found that on the contrary, they are rather irregular (right panel) and expand much more over different latitudes than originally thought. As a consequence, solar particles ejected around the equator can find their way up to the poles, and vice-versa.

This is very important as regions of the Sun, not previously considered as possible sources of hazardous particles for astronauts and satellites, must now be taken into account and carefully monitored.