FAR-ULTRAVIOLET IMAGING OF JUPITER AURORA AND THE IO FOOTPRINT

Far-ultraviolet images of Jupiter from the Hubble Space Telescope Wide Field Planetary camera 2 reveal polar auroral emissions at 300 kilome ter resolution and three times higher sensitivity than previously achi eved. Persistent features include a main oval containing most of the e mission and magnetically connected to the middle magnetosphere, diffus e and variable emissions poleward of the main oval, and discrete emiss ion from Io's magnetic footprint equatorward of the oval. The auroral emissions are variable, exhibit magnetic conjugacy, and are visible ab ove the planet limb. All emissions approximately co-rotate with Jupite r except the Io ''footprint,'' which is fixed along Io's magnetic flux tube.