Ulysses marks its 15th anniversary

During its fifteen-year mission, Ulysses has unveiled a wealth of features concerning our Sun and the interplanetary environment under its influence, the heliosphere. For example, Ulysses found out that the Sun's magnetic field reverses its polarity in an unexpectedly simple way. From the unique vantage point of view of a polar orbit around the Sun, Ulysses found out the the solar magnetic axis simply flips by 180 degrees over the course of its 11-year magnetic cycle.