Primordial noble gases in micrometeorites and interplanetary dust

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Of all the elements, noble gases have been least affected by secondary processes taking place in and on planetary bodies; accordingly, their inventory in today’s planetary atmospheres resembles most closely that which they acquired in the early days of the Solar System. Among the possible sources, which also may have made an important contribution to other volatile elements or compounds (nitrogen, water), are asteroidal and cometary bodies. The main flux of extraterrestrial material hitting Earth today is in the form of micrometeorites (MMs; sizes on the order of 100 μm); however abundances and isotopic compositions of noble gases in MMs (with the exception of implanted solar wind He and Ne) are practically unknown at this time. The aim of the project is the analysis of all the noble gases in MMs and comparison of elemental and isotopic abundance patterns with those of other known Solar System reservoirs. Analyses will be performed using a new type of noble gas mass spectrometer with multi-ion counting detector, where procedures for gas extraction and separation will first have to be optimized. The measurements shall eventually be extended to include the even smaller interplanetary dust particles (IDPs) collected in the stratosphere.