The primary function of the neutral atom imagers (NAI) carried by the IMAGE spacecraft is to provide global images of the ring current and of the hot plasmas in the inner plasma sheet as they evolve in response to disturbances in the solar wind. Using sophisticated computer programs to "deconvolve" the ion sources from the neutral atom images, researchers will be able to watch, in near real time, the ring current intensify during a geomagnetic storm and then see it fade as the storm subsides. Neutral atom imaging will also be used to image outflows of low-energy plasma from the polar ionosphere into the magnetosphere. Such outflows are a major source of magnetospheric plasma, and the IMAGE observations will help space scientists understand how their strength and composition vary with geomagnetic and solar activity, local time, and season.

In addition to looking inward, at the inner magnetosphere, IMAGE will direct its NAI instruments outward as well, to detect energetic neutral atoms associated with the passage of coronal mass ejections (CMEs) through the interplanetary medium. CMEs are violent eruptions of matter from the Sun's atmosphere that disturb the interplanetary medium and, when they hit the Earth's magnetosphere, can trigger severe geomagnetic storms, threatening spacecraft operations and astronaut safety, communications, and power transmission. Detection of ENA emissions from CMEs will give researchers a new tool for studying the propagation of CMEs through the interplanetary medium and may also provide advance warning of the onset of magnetic storms.

Topics that neutral atom imaging will be used to address include:

Ring Current

Ionospheric Plasma Outflow

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