Collaborative Research: Formation, Stability, and Detection of Amorphous Ferric Sulfate Salts on Mars

准确测定行星的表面成分对于理解塑造我们太阳系的过程至关重要。在地球之外，矿物学研究使用望远镜，轨道卫星，以及火星，着陆器和漫游者的观测。必须有精确的测量“图书馆”，显示不同的矿物如何反射不同颜色的光。如果没有比较样本，则无法进行匹配。地球上常见的物质已经被很好地研究过了。然而，火星表面还没有很好地描述在地球研究中常见的材料。富含水（“水合”）的非晶体物质（“无定形”）在火星上无处不在，但在地球上却没有得到很好的研究。研究人员建议为可能在火星上发现的水合无定形材料创建一个反射率测量库。他们将研究光反射率如何随温度变化，以及酸的风化如何改变样品的反射率。他们将包括本科生在研究中，并期望至少有六个本科论文或独立的研究项目将从这个项目中出现。作为共同PI，Dyar是Mount霍利奥克的一名教员这项工作的目的是确定无定形硫酸铁盐和盐混合物的稳定性和转化产物，测量可能的风化层材料的光谱，a）涂有这些材料和B）与这些材料混合;利用实验室光谱寻找和绘制无定形硫酸铁、无定形混合盐火星勘测轨道飞行器紧凑型火星勘测成像光谱仪（CRISM）和火星全球勘测者热发射光谱仪（TES）中的无定形盐涂层该奖项反映了NSF的法定使命，并被认为是值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估的支持。

An accurate determination of the surface composition of planets is essential for understanding the processes that have shaped our Solar System. Beyond Earth, mineralogy is studied using observations from telescopes, orbiting satellites, and in the case of Mars, landers and rovers. It is essential to have accurate "libraries" of measurements showing how different minerals reflect light of different colors. Without comparison samples, a match cannot be made. Materials that are common on Earth have been well studied. However, the surface of Mars is not yet well described in terms of materials that are common in terrestrial studies. Non-crystalline materials ("amorphous") that are rich in water ("hydrated") are ubiquitous on Mars yet are not well studied on Earth. The investigators propose to create a library of reflectance measurements for hydrated amorphous materials that are likely to be found on Mars. They will study how the light reflectance varies with temperature, and how weathering by acids changes the reflectance of a sample. They will include undergraduate students in the research and expect that at least six undergraduate thesis or independent study projects will emerge from this project. As co-PI Dyar is a faculty member at Mount Holyoke (a women's college) and the Five Colleges Astronomy Consortium, many of the student participants are expected to be women.The objectives of the work are to determine the stability and transformation products of amorphous ferric sulfate salts and salt mixtures, measure the spectra of possible regolith materials a) coated with these materials and b) mixed with these materials; and to use the laboratory spectra to search for and map spectral features of amorphouse ferric sulfates, amorphous mixed salts, and amorphous salt coatings in Mars Reconnaissance Orbiter Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) and Mars Global Surveyor Thermal Emission Spectrometer (TES) data.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.