Retherford K D, Spencer J R, Stern S A, Saur J, Strobel D F, Steffl A J, Gladstone G R, Weaver H A, Cheng A F, Parker J Wm, Slater D C, Versteeg M H, Davis M W, Bagenal F, Throop H B, Lopes R M C, Reuter D C, Lunsford A, Conard S J, Young L A, Moore J M
Southwest Research Institute, San Antonio, TX 78228, USA.
Science. 2007 Oct 12;318(5848):237-40. doi: 10.1126/science.1147594.
The New Horizons (NH) spacecraft observed Io's aurora in eclipse on four occasions during spring 2007. NH Alice ultraviolet spectroscopy and concurrent Hubble Space Telescope ultraviolet imaging in eclipse investigate the relative contribution of volcanoes to Io's atmosphere and its interaction with Jupiter's magnetosphere. Auroral brightness and morphology variations after eclipse ingress and egress reveal changes in the relative contribution of sublimation and volcanic sources to the atmosphere. Brightnesses viewed at different geometries are best explained by a dramatic difference between the dayside and nightside atmospheric density. Far-ultraviolet aurora morphology reveals the influence of plumes on Io's electrodynamic interaction with Jupiter's magnetosphere. Comparisons to detailed simulations of Io's aurora indicate that volcanoes supply 1 to 3% of the dayside atmosphere.
“新视野号”（NH）宇宙飞船在2007年春季四次观测到木卫一处于日食状态时的极光。“新视野号”的爱丽丝紫外光谱仪以及日食期间哈勃太空望远镜同时进行的紫外成像，研究了火山对木卫一大气层的相对贡献及其与木星磁层的相互作用。日食开始和结束后极光亮度和形态的变化揭示了升华源和火山源对大气层相对贡献的变化。在不同几何条件下观测到的亮度，最好用昼侧和夜侧大气密度的巨大差异来解释。远紫外极光形态揭示了羽状物对木卫一与木星磁层电动力相互作用的影响。与木卫一极光详细模拟结果的比较表明，火山为昼侧大气层提供了1%至3%的物质。
