Drifting Maxwellian fits to the ion flux from the data of Fig. 2 for the period 10:30–11:30 UT and the IES look directions indicated. Water ions are in the peak labeled (a) and solar wind ions are in the peak labeled (b). For water, the flow velocity was 72 km s⁻¹, the density was 4.0 cm s⁻³, and the temperature was 12 eV. For protons, the velocity was 470 km s⁻¹, and the density was 0.35 cm s⁻³.