Effect of Hydrogen on the Sulfur-rich Martian Core

过去二十年来对火星的研究已经确定，在火星历史的早期，气候足够温暖，水可以在其表面流动。 在今天的火星表面上还没有发现液态水，因为火星表面太冷，大气层太薄。这种变化的原因可能是地球的全球磁场的损失，允许太阳辐射剥离大气层。 这意味着地球的核心发生了重大变化，关闭了负责磁场的发电机。氢在火星核心的动力学和结构中的作用知之甚少。已知氢在高压下与金属铁形成合金。该计划将在火星核心预期的压力和温度条件下对此类合金的相关系进行系统研究。 这项研究将为亚利桑那州立大学的本科生提供全面的研究经验。本研究所激发的教学模块将在亚利桑那州立大学的编码和数据分析课程中实施。该项目的主要目标是通过进行实验来测量Fe-S-H系统在预计存在于火星核心的25-40千兆帕斯卡（GPs）压力下的熔化行为和亚固相线相关系，从而促进对火星核心动力学和结构的理解。 为了实现这一目标，将进行一系列高压、高温实验，以：（1）可能的可接受性（或溶解度）的差距Fe-S-H系统在高压和高温条件下有关火星核心，（2）氢对硫化物合金熔化温度的影响;（3）Fe-S-Al合金中的亚固相线相关系。该奖项反映了NSF的法定使命，并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，被认为值得支持。

Studies of Mars over the past twenty years have determined that early in its history the climate was warm enough for water to flow on its surface. Liquid water is not found on the surface of Mars today, because the surface is too cold and the atmosphere too thin. The cause of this change might be the loss of the planet’s global magnetic field, allowing the solar radiation to strip the atmosphere. This would imply a major change took place in the planet’s core, shutting off the dynamo responsible for the magnetic field. The role of hydrogen in the dynamics and structure of the Martian core is poorly understood. Hydrogen is known to form alloys with metallic iron at high pressure. This program will conduct a systematic study of the phase relations of such alloys at the pressure and temperature conditions expected for the Martian core. This research will provide Arizona State University undergraduate students with comprehensive research experiences. Teaching modules motivated by this research will be implemented in coding and data analysis courses at ASU. The primary goal of this project is to advance the understanding of the dynamics and structure of the Martian core by conducting experiments to measure the melting behavior and sub-solidus phase relations in Fe-S-H systems at pressures of 25-40 Gigapascals (GPs) expected to exist at the Martian core. To achieve this goal a series of high-pressure, high temperature experiments will be conducted for: (1) possible miscibility (or solubility) gaps in Fe-S-H systems at high pressure and high temperature conditions relevant to the Martian core, (2) the effects of hydrogen on the melting temperature of sulfide alloys and (3) sub-solidus phase relations in Fe-S-H systems at high pressures and high temperatures.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.