标题： 木星磁层中电磁耦合尘埃的观测 显示英文标题

标题： Observations of electromagnetically coupled dust in the Jovian magnetosphere

摘要： 我们报告了伽利略号航天器在围绕木星的第七次轨道运行期间获得的尘埃测量数据。 %其中有一次接近盖尼米德的飞越。 观测到的最显著特征是贯穿整个木星系统的高时间变化性尘埃流。 撞击率的变化幅度超过了一个数量级，并且具有5小时和10小时的周期性，这显示出与伽利略号相对于木星磁场位置的相关性。 这种行为可以通过纳米级尘埃与木星磁场的强耦合来定性解释。 除了5小时和10小时的周期性外，在尘埃撞击率中还明显存在一个与木卫一轨道周期兼容的更长周期。 这一特征表明，木卫一很可能是尘埃流的来源。 在1997年4月5日距离盖尼米德3,095公里高度的一次近距离飞越中，观察到了尘埃撞击率的增强，这表明盖尼米德可能是喷射粒子的来源。 在距离木星约25个 $\rm R_J$ （木星半径， $\rm R_J = 71,492$ 公里）范围内记录到了微米级颗粒的撞击，这些颗粒可能是围绕木星运行的束缚轨道上的粒子。 显示英文摘要

摘要： We report on dust measurements obtained during the seventh orbit of the Galileo spacecraft about Jupiter. %which had a close flyby at Ganymede. The most prominent features observed are highly time variable dust streams recorded throughout the Jovian system. The impact rate varied by more than an order of magnitude with a 5 and 10 hour periodicity, which shows a correlation with Galileo's position relative to the Jovian magnetic field. This behavior can be qualitatively explained by strong coupling of nanometer-sized dust to the Jovian magnetic field. In addition to the 5 and 10 h periodicities, a longer period which is compatible with Io's orbital period is evident in the dust impact rate. This feature indicates that Io most likely is the source of the dust streams. During a close (3,095 km altitude) flyby at Ganymede on 5 April 1997 an enhanced rate of dust impacts has been observed, which suggests that Ganymede is a source of ejecta particles. Within a distance of about 25 $\rm R_J$ (Jupiter radius, $\rm R_J = 71,492$ km) from Jupiter impacts of micrometer-sized particles have been recorded which could be particles on bound orbits about Jupiter.