论文标题
Europa上的新紫外光谱功能：确认NaCl在领先的山脉混乱地形中
A New UV Spectral Feature on Europa: Confirmation of NaCl in Leading-hemisphere Chaos Terrain
论文作者
论文摘要
最近，使用哈勃太空望远镜获得的欧罗巴表面的可见波长观察结果表明，在450 nm附近的吸收特征的存在似乎与领先的山脉混乱的地形在空间上相关。该特征被解释为反映了最终来自内部的辐照氯化钠的存在。在这里，我们使用与哈勃空间望远镜收集的紫外光谱，以检测230 nm附近的其他先前看不见的吸收，这在空间上与450 nm的特征和相同的领先半球混乱的地形相同。我们发现，在类似欧罗巴的条件下，辐射的氯化钠也可以很好地匹配新的紫外线。这种确认地质年轻区域内氯化钠对欧罗巴地下组成具有重要意义。
Recent visible-wavelength observations of Europa's surface obtained with the Hubble Space Telescope revealed the presence of an absorption feature near 450 nm that appears spatially correlated with leading-hemisphere chaos terrain. This feature was interpreted to reflect the presence of irradiated sodium chloride ultimately sourced from the interior. Here, we use ultraviolet spectra also collected with the Hubble Space Telescope to detect an additional previously unseen absorption near 230 nm, which spatially correlates with the 450 nm feature and with the same leading-hemisphere chaos terrain. We find that the new ultraviolet feature is also well-matched by irradiated sodium chloride at Europa-like conditions. Such confirmation of sodium chloride within geologically young regions has important implications for Europa's subsurface composition.
