Past solar wind flux recorded in solar-gas-rich meteorites

Tomoya Obase, Daisuke Nakashima

研究成果: Article査読


Astronomical observations of solar-like stars and theoretical predictions have proposed a high long-term average solar wind flux in the past, such as more than ∼10 times higher than the present-day value at ∼3 Ga. Solar-gas-rich meteorites are lithified asteroidal regolith materials that had been exposed to solar wind in the past and some of which may record the ancient solar wind. To test the hypothesis of dense solar wind in the past Solar System, we quantified the past solar wind 36Ar particle fluxes based on the correlations between the solar and cosmogenic noble gas concentrations in individual solar-gas-rich meteorites. As a result, the past solar wind fluxes recorded in six solar-gas-rich meteorites were comparable to the present-day value except for the R chondrite PRE 95410, showing a few times higher solar wind flux. The howardite Kapoeta perhaps records the solar wind flux at some time between ∼1 and ∼2 Ga, suggesting that the solar wind flux in the past at least ∼1 Ga had been similar to the present-day value. These results may indicate that the past solar wind flux had been lower than that proposed by the astronomical observations and the theoretical predictions. Otherwise, the six meteorites would have acquired recent solar wind when the solar wind flux had already been down to the present-day level.

出版ステータスPublished - 2023 1月 1

ASJC Scopus subject areas

  • 天文学と天体物理学
  • 宇宙惑星科学


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