The noble gas and nitrogen relationship between Ryugu and carbonaceous chondrites

Noble gas mass-spectrometry for extraterrestrial micro-samples: analyses of asteroid matter returned by Hayabusa2 JAXA mission

“…A close relationship between Ryugu and CI chondrites was previously suggested based on the nitrogen and noble gases data. 27 Interestingly, the release of radiogenic iodine-derived 129* Xe in magnetite separated from CI carbonaceous chondrite Orgueil is characterized by two major peaks; 37 the low temperature one in a 900–1050 °C range, similar to what is observed here for the Ryugu samples. The presence of magnetite is a marker of aqueous activity.…”

“…The small mass of Ryugu material available for initial analyses limited the number of temperature steps. Recent studies of Ryugu noble gases 26,27 typically used 2-4 laser heating steps, which is not sufficient for satisfactory resolution of various noble gas components. We studied similarly sized samples, but our experimental setup allowed us to analyse all noble gas isotopes in 7 steps for the 82 mg sample (C0106-05) and 11 steps for the 173 mg sample (A0105-04) with the same or better precision.…”

“…Considering all the noble gas isotopes together, our data confirm the presence of the HL component in both samples analysed in this work, hence, resolving the doubts about its presence in Ryugu samples. 27…”

“…The sample loading procedures along with sample weighting were performed in dry nitrogen, following the intricate protocol developed by Kyushu University (ref. 26 and 27).…”

A new primordial noble gas component in the solar system discovered in Ryugu asteroid

“…Data for bulk noble gases, nitrogen and carbon concentrations and Ne, N and C isotopic compositions in the Ryugu samples and in three CI meteorites, some of which were analysed in the present study, are shown in Table 1. For comparison, the ranges of noble gases, nitrogen and carbon concentrations and Ne, C and N isotopic compositions analysed in Ryugu samples in other studies [23][24][25][26] are also shown. As can be seen from Table 1, 4 He, 20 Ne, 36 Ar and 132 Xe concentrations in the Ryugu samples analysed in the present study and by Okazaki et al 23 , analysed in different laboratories all over the world, are in the same range except for 132 Xe in the sample C0209 which is an order of magnitude higher than the highest 132 Xe concentration found in other Ryugu samples 23,24 .…”