The Galileo heavy ion counter is sensitive to ions with atomic numbers Z greater than or equal to 6 and energies greater than similar to 6 MeV per nucleon, During Galileo’s passage through Jupiter’s inner magnetosphere, the observed composition of these heavy ions was consistent with the presence of singly ionized iogenic. O, Na, and S and highly ionized solar C, O, and Ne. The solar component is absorbed more strongly by Io because its gyroradius is smaller than Io’s diameter.