IPM_Protons_wbg.png
Proton density (i.e., 95% of the constitution of the solar wind) in the interplanetary medium, courtesy Pintéra et al. (2009).
Bibliography
Pintéra, T.; Dorotoviča, I.; Rybanský, M. (2009): The heliosphere mass variations: 1996–2006. Proceedings of the International Astronomical Union, 4 (257): 291-293