Dim ENA Emissions from ~1-30 keV McComas, D. J., P. Valek, J. L. Burch, and C. J. Pollock, H. O. Funsten, R. M. Skoug, M. F. Thomsen The Medium Energy Neutral Atom (MENA) instrument on IMAGE routinely observes ENA emissions from the region around the Earth. These emissions are further enhanced during transient magnetospheric phenomena such as storms and substorms. In contrast to these relatively "bright" emissions, this study examines the very "dim" ENA emissions observed by MENA when it is looking further away from the Earth. In order to quantify these emissions, we first investigated the source of elevated backgrounds periodically observed by MENA. We find that elevated background rates are well correlated with enhanced GOES 8 proton fluxes in the 0.7Ð 4 MeV range. When these fluxes drop below ~10 cm-2 s sr MeV, MENA count rates nearly flatten out, indicating the dim ENA and instrumental background rates. During these quiet periods, we occasionally observe emissions from the more distant plasma sheet, and find an apparent annual variation in the background rates, which may be direct observations of heliospheric ENAs. _______________ To be presented at the Magnetospheric Imaging Workshop, Yosemite National Park, California, U.S.A., Feb. 5-8, 2002.