Streams of high speed dust particles originate from Jupiter's moon Io. After release from Io, the particles collect electric charges in the Io plasma torus, gain energy from the co-rotating electric field of Jupiter's magnetosphere, and leave the Jovian system into interplanetary space with escape speeds over 200 km s−1. The Galileo spacecraft has continuously monitored the dust streams during 34 revolutions about Jupiter between 1996 and 2002. The observed dust fluxes exhibit large orbit-to-orbit variability due to systematic and stochastic changes. After removal of the systematic variations, the total dust emission rate of Io has been calculated. It varies between 10−3 and 10 kg s−1, and is typically in the range of 0.1 to 1 kg s−1. We compare the dust emission rate with other markers of volcanic activity on Io like large-area surface changes caused by volcanic deposits and sightings of volcanic plumes.
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机译:高速尘埃粒子流起源于木星的月亮艾。从Io释放后,这些粒子在Io等离子体圆环中收集电荷,从木星磁层的同向旋转电场中获取能量,并以逃逸速度超过200 km s-1离开木星系统进入行星际空间。伽利略号航天器在1996年至2002年期间围绕木星进行了34次旋转期间,不断监测着尘埃流。由于系统的和随机的变化,观测到的尘埃通量呈现出较大的轨道间变化性。消除系统差异后,已计算出Io的总粉尘排放率。它在10-3和10 kg s-1之间变化,通常在0.1到1 kg s-1之间。我们将粉尘排放率与Io上火山活动的其他标志物进行了比较,例如由火山沉积物和发现的火山羽引起的大面积表面变化。
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