Mora Maria F, Jones Steve M, Creamer Jessica, Willis Peter A
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA.
Electrophoresis. 2018 Feb;39(4):620-625. doi: 10.1002/elps.201700323. Epub 2017 Dec 8.
Ocean worlds like Europa and Enceladus in the outer solar system are prime targets in the search for life beyond Earth. Enceladus is particularly interesting due to the presence of a water plume ejecting from the south polar region. The recent discovery of H in the plume, in addition to the presence of previously observed organic compounds, highlights the possibility of life in this moon. The plume provides materials from the underlying ocean that could be collected simply by flying through it. The presence of the plume means that material from the ocean is available for collection during a flyby, without the need for landing or complex sample handling operations such as scooping or drilling. An attractive approach to preserve the organics in particles collected during flyby encounters would be to utilize silica aerogel, the material used to collect particles at hypervelocity during the Stardust mission. Here we demonstrate amino acids can be extracted from aerogel simply by adding water. This simple liquid extraction method could be implemented during a mission prior to analysis with a liquid-based technique like capillary electrophoresis.
像太阳系外层的木卫二和土卫二这样的海洋世界是寻找地球以外生命的主要目标。土卫二特别有趣，因为它的南极地区有一股羽流喷出。最近在羽流中发现了氢，再加上之前观察到的有机化合物的存在，凸显了这颗卫星存在生命的可能性。羽流提供了来自其下方海洋的物质，只需飞过羽流就能收集到这些物质。羽流的存在意味着在飞越过程中可以收集来自海洋的物质，而无需着陆或进行诸如挖掘或钻探等复杂的样本处理操作。一种在飞越过程中收集的颗粒中保存有机物的有吸引力的方法是利用二氧化硅气凝胶，这是“星尘”任务期间用于以超高速收集颗粒的材料。在这里，我们证明了只需加水就能从气凝胶中提取氨基酸。这种简单的液体提取方法可以在任务期间实施，然后再用基于液体的技术（如毛细管电泳）进行分析。
