• Search Research Projects
  • Search Researchers
  • How to Use
  1. Back to previous page

Searcg for the signatures of solar super-flare in lunar regolith grains

Research Project

Project/Area Number 17K18807
Research Category

Grant-in-Aid for Challenging Research (Exploratory)

Allocation TypeMulti-year Fund
Research Field Earth and planetary science and related fields
Research InstitutionKyushu University

Principal Investigator

Noguchi Takaaki  九州大学, 基幹教育院, 教授 (40222195)

Co-Investigator(Kenkyū-buntansha) 日高 洋  名古屋大学, 環境学研究科, 教授 (10208770)
岡崎 隆司  九州大学, 理学研究院, 准教授 (40372750)
Project Period (FY) 2017-06-30 – 2021-03-31
Project Status Completed (Fiscal Year 2020)
Budget Amount *help
¥6,240,000 (Direct Cost: ¥4,800,000、Indirect Cost: ¥1,440,000)
Fiscal Year 2019: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2018: ¥3,380,000 (Direct Cost: ¥2,600,000、Indirect Cost: ¥780,000)
Fiscal Year 2017: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Keywordsソーラーフレアトラック / 太陽風 / 鉄ウィスカ / 宇宙風化 / 太陽活動 / 超高圧電子顕微鏡 / 月レゴリス / トモグラフィ / 可視化 / 照射実験 / 太陽フレア / トラック / スーパーフレア / 透過電子顕微鏡 / 同位体
Outline of Final Research Achievements

We tried to obtain distribution of length of solar flare tracks in lunar regolith samples using mild heating in the atmosphere. However, visualization of solar flare tracks did not occur by mild heating (300 oC) in the atmosphere.Nextly, we tried to obtain distribution of length of solar flare tracks in lunar regolith samples by high-voltage transmission electron (HVEM) observation of thick (~2 microns) sections. But the distribution of length of solar flare tracks were not obtained even by using such thick sections.
During the course of these studies, we found Fe sulfide grains with very strange texture and morphology. The sulfide grains have Tafoni-like porous surfaces. There were sinuous striated object that seemed to have grown from the surfaces of the Fe sulfide grains. We investigated them with Dr. Toru Matsumoto, PD in my laboratory. The lunar iron whiskers grew to be much larger than those on the Itokawa grains, which reflected the different exposure to the solar activity.

Academic Significance and Societal Importance of the Research Achievements

月試料は長期に渡る太陽活動の記録をとどめている。太陽フレアトラックの長さ分布を求めることから,長期間の太陽活動を調べることができると考えて,本研究を始めた。しかし,研究期間内に太陽フレアトラック長を使って太陽活動を調べることは成功しなかった。しかし,太陽活動の長期記録を保持している新たな組織を発見した。それは硫化鉄表面に成長している金属鉄ウィスカである。このウィスカは,1万年程かけて成長していた可能性が高く,新たな太陽活動の指標となると考えられる。硫化鉄は小惑星リュウグウにも存在するため,この試料からも金属鉄ウィスカを見いだして太陽活動について議論できるものと考えられる。

Report

(5 results)
  • 2020 Annual Research Report   Final Research Report ( PDF )
  • 2019 Research-status Report
  • 2018 Research-status Report
  • 2017 Research-status Report
  • Research Products

    (1 results)

All 2021

All Journal Article (1 results) (of which Int'l Joint Research: 1 results,  Peer Reviewed: 1 results)

  • [Journal Article] Space weathering of iron sulfides in the lunar surface environment2021

    • Author(s)
      Matsumoto Toru、Noguchi Takaaki、Tobimatsu Yu、Harries Dennis、Langenhorst Falko、Miyake Akira、Hidaka Hiroshi
    • Journal Title

      Geochimica et Cosmochimica Acta

      Volume: 299 Pages: 69-84

    • DOI

      10.1016/j.gca.2021.02.013

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed / Int'l Joint Research

URL: 

Published: 2017-07-21   Modified: 2022-01-27  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi