File:Earth plasmasphere in EUV.jpg

The Extreme Ultraviolet imager (EUV) instrument on board IMAGE captured this picture of the ultraviolet glow from relatively cold plasma surrounding our planet. A hook-shaped "tail" of plasma, near the top-right, streams toward the Sun. The small, faint circle near the center of the image traces ultraviolet radiation from aurora borealis (or "Northern Lights"). The "relatively cold plasma" is the Earth's plasmasphere. The small hook at left, unfortunately cited as a "tail" in the NASA press release, is not a magnetic tail like the Earth's huge magnetotail, but a relatively small peeling off of material from the plasmasphere. For full description, see http://science.nasa.gov/headlines/y2001/ast25jan_1.htm. See also the discussion page.