Bickel V T, Thomas N, Pommerol A, Tornabene L L, El-Maarry M R, Rangarajan V G
Center for Space and Habitability, University of Bern, Bern, Switzerland.
Physikalisches Institut, University of Bern, Bern, Switzerland.
Sci Data. 2024 Aug 3;11(1):845. doi: 10.1038/s41597-024-03685-3.
Chloride deposits are markers for early Mars' aqueous past, with important implications for our understanding of the martian climate and habitability. The Colour and Stereo Surface Imaging System (CaSSIS) onboard ESA's Trace Gas Orbiter provides high-resolution color-infrared images, enabling a planet-wide search for (small) potentially chloride-bearing deposits. Here, we use a neural network to map potentially chloride-bearing deposits in CaSSIS images over a significant fraction of the planet. We identify 965 chloride deposit candidates with diameters ranging from <300 to >3000 m, including previously unknown deposits, 136 (~14%) of which are located in the highlands north of the equator, up to ~36°N. Northern chloride candidates tend to be smaller than in the south and are predominantly located in small-scale topographic depressions in low-albedo Noachian and Hesperian highland terranes. Our new dataset augments existing chloride deposit maps, informs current and future imaging campaigns, and enables future modelling work towards a better understanding of the distribution of near-surface water in Mars' distant past.
氯化物沉积物是早期火星存在水的标志，对我们理解火星气候和宜居性具有重要意义。欧洲航天局（ESA）的痕量气体轨道器上搭载的彩色立体表面成像系统（CaSSIS）可提供高分辨率彩色红外图像，从而能够在全球范围内搜索（小型）潜在的含氯化物沉积物。在此，我们使用神经网络在该行星的很大一部分区域内绘制CaSSIS图像中的潜在含氯化物沉积物。我们识别出965个直径范围从小于300米到大于3000米的氯化物沉积物候选体，包括先前未知的沉积物，其中136个（约14%）位于赤道以北高达约北纬36°的高地。北半球的氯化物候选体往往比南半球的小，并且主要位于低反照率的诺亚纪和晚赫斯珀里亚纪高地地形中的小规模地形凹陷处。我们的新数据集扩充了现有的氯化物沉积物地图，为当前和未来的成像任务提供了信息，并有助于未来开展建模工作，以更好地了解火星遥远过去近地表水的分布情况。
