Figure 9-19A Snapshot of the Sun’s Global Magnetic Field By following the paths of particles emitted by a solar flare, astronomers have begun mapping the solar magnetic field outside the Sun. The field guides the outflowing particles, which, in turn, emit radio waves that indicate the position of the field. These data were collected by the Ulysses spacecraft in 1994. Ulysses was the first spacecraft to explore interplanetary space from high above the plane of the ecliptic.