Evaluation of the Interplanetary Magnetic Field Strength Using the Cosmic-Ray Shadow of the Sun

How the Sun's magnetic field, in a region hardly open to in situ measurement, can be inferred from the deflection of cosmic rays in the TeV energy range. This technique, now demonstrated by several huge arrays set up to detect high-energy cosmic rays via their air-shower development, is sensitive enough to detect annual variability and thence the solar cycle, and in addition can distinguish "away" from "towards" sector structures.

      Note that the authors of this (and earlier) pioneering papers on this topic were too dignified to put a colorful cartoon in their research paper directly. This is from the press release issued by their eager sponsors. Note also that the legends neatly read Cosmic Rays, Sun and Earth, probably distinguishable in the graphic.