论文标题
来自Messenger X射线光谱仪观测值的全球主要元素图
Global Major-Element Maps of Mercury from Four Years of MESSENGER X-Ray Spectrometer Observations
论文作者
论文摘要
信使航天器上的X射线光谱仪（XRS）提供了对汞表面的主要元素比率的测量。我们介绍了Mg/si，al/si，s/si，ca/si和fe/si的全球地图，这些图从整个Messenger的轨道任务中收集的XRS数据得出。我们描述了我们用来选择和过滤数据并将它们组合以制作最终地图的过程，该图已存档在NASA的行星数据系统中。面积的覆盖范围是不同元素比率地图的可变范围，Mg/si和al/si的覆盖率为100％，但在30 $^{\ circ} $ n以北的Fe/Si覆盖率只有18％，其中空间分辨率最高。由于在飞船围绕Periapsis的高度较低时，在任务后期包含了更高分辨率的数据，因此空间分辨率比以前的地图提高了10-15％。但是，与典型的行星数据图不同，XRS图的空间分辨率可能因像素而异，因此在解释小规模特征时必须注意。我们提供了几个示例，说明了如何使用XRS地图来研究汞的地质特征的元素变化，汞的大小从单个$ \ sim $ \ sim $ \ sim $ 100公里直径的陨石坑到大撞击盆地。我们预计这些地图将为未来多年的汞起源和地质历史研究提供基础和/或为研究的基础。
The X-Ray Spectrometer (XRS) on the MESSENGER spacecraft provided measurements of major-element ratios across Mercury's surface. We present global maps of Mg/Si, Al/Si, S/Si, Ca/Si, and Fe/Si derived from XRS data collected throughout MESSENGER's orbital mission. We describe the procedures we used to select and filter data and to combine them to make the final maps, which are archived in NASA's Planetary Data System. Areal coverage is variable for the different element-ratio maps, with 100% coverage for Mg/Si and Al/Si, but only 18% coverage for Fe/Si north of 30 $^{\circ}$ N, where the spatial resolution is highest. The spatial resolution is improved over previous maps by 10-15% because of the inclusion of higher-resolution data from late in the mission when the spacecraft periapsis altitude was low. Unlike typical planetary data maps, however, the spatial resolution of the XRS maps can vary from pixel to pixel, and thus care must be taken in interpreting small-scale features. We provide several examples of how the XRS maps can be used to investigate elemental variations in the context of geological features on Mercury, which range in size from single $\sim$100-km-diameter craters to large impact basins. We expect that these maps will provide the basis for and/or contribute to studies of Mercury's origin and geological history for many years to come.
