Experimental Investigation of Planetary Atmospheres

对火星的探索解决了关于生命可居住性的最深刻的问题，无论是在遥远的过去还是现在。每一次火星探测使命的发现都提供了拼图的碎片，而迄今为止最关键的进展与水有关。有证据表明，在遥远的过去，火星上有液态水流动，据了解，在地球的历史上，大部分水已经逃逸到太空中。水逸出大气的速率取决于从地表到高层大气的传输路径。火星大气中的云是由冰晶组成的，这些冰晶长大到足以沉淀到火星表面。这是一种在空气上升到高层大气时使空气脱水的机制，将水限制在较低的高度。云和降水是地球上水流失速度的重要因素，因此也是火星上水的历史。该研究计划的目标之一是调查云和降水在空气通过火星大气层上升时脱水的作用。目前正在利用目前在火星轨道上的欧洲航天局痕量气体轨道器使命上的NOMAD仪器对云和水蒸气进行测量。这些测量结果正在使用计算机模拟模型进行解释，以追踪火星大气层中空气包的路径。 该研究计划的另一个目标涉及火星表面和大气之间的水交换。这对理解火星表面下大量水冰的起源有影响。美国宇航局凤凰号火星使命期间的一项重要发现是在表面物质中鉴定出高氯酸盐。高氯酸盐在火星上的水研究中具有很大的意义，因为它能够将大气中的水蒸气吸收到凝固点低至-67摄氏度的液体溶液中。火星表面可能存在液态水。这具有有趣的生物学意义，因为这种液体盐水溶液可能为生物体提供可居住的环境。目前正在开发一种新的仪器，在实验室中研究这一过程，并在环境室内重现火星表面的条件。长期目标是在着陆的航天器上用该仪器的小型化版本在火星表面进行调查。 经过培训的学生将获得在加拿大科学和工业中广泛使用的光学技术和分析方法的技能。为未来的火星使命贡献一台仪器将使加拿大受益，因为来自加拿大各大学的多学科学术团体将组成科学小组，加拿大空间工程工业将建造空间合格仪器。

Exploration of Mars addresses the most profound questions concerning habitability for life, either in the distant past or the present. The findings from each Mars exploration mission provide pieces of the puzzle and the most crucial advancements so far concern water. There is evidence for flowing liquid water on Mars in the distant past and it is understood that much of that water has escaped to space over the history of the planet. The rate at which the water escapes the atmosphere is dependent on the transport pathways from the surface to the upper atmosphere. Clouds in the atmosphere of Mars are composed of ice crystals that grow large enough to precipitate to the surface. This is a mechanism for dehydrating the air as it ascends to the upper atmosphere, confining water to lower altitudes. The clouds and precipitation are a significant factor in the rate at which water is lost from the planet and thus also in the history of water on Mars. One of the objectives of the research program is to investigate the role of clouds and precipitation in dehydrating air as it ascends through the atmosphere of Mars. This is being carried out using measurements of clouds and water vapour from the NOMAD instrument on the European Space Agency Trace Gas Orbiter mission that is currently in orbit at Mars. These measurements are being interpreted using a computer simulation model to trace the path of air parcels through the atmosphere of Mars.     Another objective of the research program concerns the exchange of water between the surface and the atmosphere on Mars. This has implications for understanding the origin of the vast amount of water ice below the surface of Mars. An important discovery during the NASA Phoenix Mars mission was the identification of perchlorate salt in the surface material. Perchlorate salt is of great interest for studies of water on Mars due to its ability to absorb water vapour from the atmosphere into a liquid solution with a freezing point that is as low as -67 degrees Celsius. It is possible that liquid water occurs on the surface of Mars. This has intriguing biological implications since such a liquid brine solution could potentially provide a habitable environment for living organisms. A new instrument is being developed to investigate this process in the laboratory with the conditions on the surface of Mars being recreated within an environmental chamber. The long-term goal is to carry out the investigation on the surface of Mars with a miniaturized version of the instrument on a landed spacecraft.     Trained students will gain skills in optical technologies and analysis methods that are of widespread use in Canadian science and industry. Contribution of an instrument for a future Mars mission will be a benefit to Canada as a multidisciplinary group of academics from various Canadian universities would compose the science team, and the Canadian space engineering industry would construct the space qualified instrument.