FIGURE 1. Energetic neutral atom image of Jupiter's magnetosphere as viewed from the dusk meridian soon after Cassini's closest approach on 30 December 2000.
From the following article:
A nebula of gases from Io surrounding Jupiter
Stamatios M. Krimigis, Donald G. Mitchell, Douglas C. Hamilton, Jannis Dandouras, Thomas P. Armstrong, Scott J. Bolton, Andrew F. Cheng, George Gloeckler, K. C. Hsieh, Edwin P. Keath, Norbert Krupp, Andreas Lagg, Louis J. Lanzerotti, Stefano Livi, Barry H. Mauk, Richard W. McEntire, Edmond C. Roelof, Berend Wilken and Donald J. Williams
Nature 415, 994-996(28 February 2002)
doi:10.1038/415994a
The image was generated by neutrals in the range (3–4) 
103 km s-1 or 
50–80 keV per nucleon, assuming the species to be hydrogen. The location of Io's plasma torus has been sketched in (dark lines, centre) and Jupiter's magnetic field (white lines) superimposed on the image for reference.