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

准确确定行星的表面组成对于理解塑造我们太阳系的过程是至关重要的。除了地球之外，矿物学的研究是通过望远镜、轨道卫星以及火星、着陆器和漫游车的观测来进行的。有准确的测量“库”来显示不同矿物如何反射不同颜色的光是至关重要的。没有比较样本，就无法进行匹配。地球上常见的材料已经得到了很好的研究。然而，就地球研究中常见的材料而言，火星表面还没有得到很好的描述。富含水的非晶态物质(水合物质)在火星上无处不在，但在地球上却没有得到很好的研究。研究人员提议为可能在火星上发现的水合无定形物质建立一个反射率测量库。他们将研究光的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。他们将把本科生包括在研究中，并预计这个项目将产生至少六个本科生论文或独立研究项目。由于co-Pi Dyar是芒特霍利奥克(一所女子学院)和五所学院天文联合会的教员，预计许多学生参与者都是女性。这项工作的目标是确定无定形硫酸铁盐和盐混合物的稳定性和转化产物，测量可能的风化材料的光谱，a)覆盖这些材料，b)与这些材料混合；并使用实验室光谱在火星勘测轨道紧凑型火星侦察成像光谱仪(CRISM)和火星全球探测器热发射光谱仪(TES)数据中搜索和绘制非晶态硫酸铁、无定形混合盐和无定形盐涂层的光谱特征。该奖项反映了NSF的法定任务，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

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.