Chikyukagaku
Online ISSN : 2188-5923
Print ISSN : 0386-4073
ISSN-L : 0386-4073
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Volume 32, Issue 4
Special Issue: “Material Science of Cosmic Dust”
Displaying 1-13 of 13 articles from this issue
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Special Issue: “Material Science of Cosmic Dust”
Review on “Material Science of Cosmic Dust”
  • Research of cosmic dust as material science
    Yuji TAZAWA, Takaaki FUKUOKA
    1998 Volume 32 Issue 4 Pages 149-159
    Published: December 15, 1998
    Released on J-STAGE: December 26, 2016
    DOIhttps://doi.org/10.14934/chikyukagaku.32.149
    JOURNAL FREE ACCESS
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    Extraterrestrial microparticles have been collected and investigated for more than a century. Recent developments of analytical techniques and mass collecting methods have brought us three types of collections and new knowledge of cosmic dust; (1) the smallest size group (smaller than 100μm) from the Stratosphere mainly consisting of the most primitive and fragile particles, most of which are unmelted porous aggregates of fine grains thought to be typical of interplanetary dust particles (IDPs) or cometary debris just falling onto the earth, (2) the largest size group (several 10 μm to several mm) from deep sea sediments, the best known cosmic dust collection as "cosmic spherules", all of which melted during atmospheric entry and were heavily weathered during their terrestrial ages, and (3) the medium size group (several μm to several 100μm) from the Polar ice/ snow mainly consisting of partially melted and unmelted particles distinct from conventional chon- dritic materials. Although quantity of a single particle is too small, compiled information obtained by the various new methods will give us a new horizon of material science of the extraterrestrial matter.
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  • Collection and Curation of Cosmic Dust
    Hajime YANO, Tomoki NAKAMURA, Wataru NOZAKI, Minoru FUNAKI, Naoya IMAE ...
    1998 Volume 32 Issue 4 Pages 161-174
    Published: December 15, 1998
    Released on J-STAGE: December 26, 2016
    DOIhttps://doi.org/10.14934/chikyukagaku.32.161
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    Since the early development of the cosmic dust research that started almost a century ago, a wide variety of the sample collection techniques has been developed. Such direct sampling of cosmic dust (or micrometeoroids, micrometeorites, interplanetary dust particles (IDP)) has enabled subsequent analyses of these extra-terrestrial micro particles at ground laboratories in great detail. In coming years, Japan will have an array of new opportunities of cosmic dust collection from space, stratosphere and Antarctica. However each collection site causes certain biases of samples in terms of physical and chemical alterations, selection effects and contamination. Here we review the cosmic dust collection from deep sea sediments, Greenland blue lakes, Antarctic ice cores, stratosphere and both near-Earth and interplanetary space, together with a brief description of the curation system of the samples being operated by NASA/JSC.
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  • Mineralogy and petrology of meteorites and cosmic dusts
    Takaaki NOGUCHI, Naoya IMAE
    1998 Volume 32 Issue 4 Pages 175-184
    Published: December 15, 1998
    Released on J-STAGE: December 26, 2016
    DOIhttps://doi.org/10.14934/chikyukagaku.32.175
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    Extraterrestorial materials are divided into two categories based on their sizes: meteorites are >1mm across, and cosmic dusts<1mm across. Because most of cosmic dusts experienced severe heating during atmospheric entry, they were melted or hydrous minerals in them were decomposed into the aggregates of anhydrous minerals. However, some cosmic dusts keep original mineralogy and petrology before atmospheric entry, due to lower peak temperatures during the entry. Mineralogy and petrology, as well as chemistry, of such cosmic dusts (many interplanetary dust particles (IDPs) and some micrometeorites) are different from those of meteorites. Therefore, it is clear that such cosmic dusts are different in origin from meteorites. Parent bodies of some pyroxene-class anhydrous IDPs and some smectite-class hydrated IDPs may be comets. On the other hand, parent bodies of most of IDPs and a part of undehydrated micrometeorites are probably asteroids which are different from the meteorite parent bodies.
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  • Chemical analysis and composition of cosmic spherules and interplanetary dust particles
    Mitsuru EBIHARA
    1998 Volume 32 Issue 4 Pages 185-191
    Published: December 15, 1998
    Released on J-STAGE: December 26, 2016
    DOIhttps://doi.org/10.14934/chikyukagaku.32.185
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    Cosmic spherules and interplanetary dust particles (IDPs) are grouped into the third category of the extraterrestrial materials, following meteorites and lunar samples. As cosmic spherules and IDPs are much smaller than meteorites, it is difficult to obtain accurate and precise data for their elemental composition. In this review article, progress in chemical analysis of cosmic spherules and IDPs is described. Of these extraterrestrial matters, cosmic spherules have been more extensively studied with respect to chemical composition, mostly by using instrumental neutron activation analysis. On the other hand, chemical study on IDPs has recently been greatly progressed. The application of synchrotron X-ray fluorescence analysis to IDPs have yielded such great, and rapid progress. In coming few years, we can expect to have a large number of cosmic spherules collected on Antarctica. Now, it is up to us whether a comparative increase in science will be realized.
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  • Isotope studies on interplanetary dust particles (IDPs) –Noble gases–
    Keisuke NAGAO
    1998 Volume 32 Issue 4 Pages 193-201
    Published: December 15, 1998
    Released on J-STAGE: December 26, 2016
    DOIhttps://doi.org/10.14934/chikyukagaku.32.193
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    Only a few laboratories have reported noble gas data for a single particle of interplanetary dust particles (IDPs) because of difficulties in analyzing extremely small particle sizes, 〜10μm and〜10ng, for which a noble gas detection system with low analytical blank level and high sensitivity is required. Noble gas studies performed on IDPs until now have been aimed at identifying their extraterrestrial origin and at estimating heating temperature experienced during their entry into the terrestrial atmosphere. Isotopic compositions of light noble gases He, Ne and Ar indicate solartype noble gas component, and strongly support their extraterrestrial origin. Step-heating experiments show variable release patterns for He and Ne depending on the thermal history of particles, which may help in identifying the origins, asteroidal or cometary, of individual particles. Noble gases of extraterrestrial origin observed in deep-sea sediments are also described.
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  • Cosmogenic nuclides in cosmic dust
    Hiroyuki MATSUZAKI
    1998 Volume 32 Issue 4 Pages 203-213
    Published: December 15, 1998
    Released on J-STAGE: December 26, 2016
    DOIhttps://doi.org/10.14934/chikyukagaku.32.203
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    Spherules, found in the deep sea sediments and the polar ice, form a unique group of cosmic dust sample. Cosmogenic nuclides such as 10Be, 26Al contained in spherules will indicate many information about not only the origin and motion of the cosmic spherules themselves but also various physical phenomena which happened in the solar system. Recently, some attempts to measure the cosmogenic nuclides in spherules are successfully done with the technique of AMS (Accelerator Mass Spectrometry). In this article, the character of the cosmic ray and the interaction between the cosmic ray and the solid body are summarized first, which is necessary to interpret the data of the AMS measurements. Then, actual data are presented and examined.
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  • Ultramicrotomy and its application to the study of meteorites and cosmic dusts
    Takaaki NOGUCHI
    1998 Volume 32 Issue 4 Pages 215-223
    Published: December 15, 1998
    Released on J-STAGE: December 26, 2016
    DOIhttps://doi.org/10.14934/chikyukagaku.32.215
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    Ultramicrotomy is the most suitable sample preparation technique for the study of mineralogy and petrology of fine-grained (<100μm across) rock fragments, such as interplanetary dust particles and unmelted micrometeorites, because we can observe wide areas(a few tens of μm across)by a transmission electron microscope (TEM). There are some difficulties to make ultrathin sections of meteorites and cosmic dusts. The difficulties are different from those to make ultrathin sections of biological samples. The author explained in detail the principle of ultramicrotomy, sample preparation procedures in the author's laboratory, variations of sample preparation techniques in other laboratories, and showed some examples of ultrathin sections of a meteorite and a interplanetary dust particle.
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Original Paper on “Material Science of Cosmic Dust”
  • Identification of cosmic dust in Antarctic ice by magnetic methods
    Minoru FUNAKI
    1998 Volume 32 Issue 4 Pages 225-232
    Published: December 15, 1998
    Released on J-STAGE: December 26, 2016
    DOIhttps://doi.org/10.14934/chikyukagaku.32.225
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    Identification of cosmic dust in Antarctic ice by magnetic methods is discussed based on the rock magnetic results of the clean-ice and dirt-ice. The cosmic dust sized several μm (in diameter) with the saturation isothermal remanent magnetization is identified by the superconducting quantum interference device (SQUID) magnetometer. The direction of natural remanent magnetization of the cosmic dust in ice is discussed. The cosmic dust may be preferably transported to Antarctica through the stratosphere atmospheric circulation. The cosmic dust may be concentrated under the ice surface of bare ice around Antarctic coasts by the interaction of precipitation of cosmic dust in melted water and ablation of ice by the solar radiation. The concentration may not occur in the high land in Antarctica due to too low temperature.
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  • Physical and chemical characteristics of magnetic spherules separated from deep sea sediment dredged off Hawaii islands
    Takayuki KOBAYASHI, Mitsuru EBIHARA
    1998 Volume 32 Issue 4 Pages 233-241
    Published: December 15, 1998
    Released on J-STAGE: December 26, 2016
    DOIhttps://doi.org/10.14934/chikyukagaku.32.233
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    Magnetic spherules were separated from the deep-sea sediments dredged off the Hawaii islands. Spherules were classified by size and magnetic property. The abundance of magnetic spherules in the sediments used in this study is 3.3 × 10-6g/g wet sediments. The trend seen in the size distribution of spherules with diameters ranging from several urn to 590μm is consistent with the reported one for magnetic spherules larger than 100μm. Twenty two magnetic spherules were individually analyzed by instrumental neutron activation analysis and Fe, Co, Ni and Ir were determined. Iridium contents, Ni/Fe ratios and Co/Fe ratios were suggested for effective criteria in discussing the origin of magnetic spherules. Judging from chemical compositions, at least 14 out of the 22 spherules analyzed in this study were inferred to be extraterrestrial in origin.
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Abstract of doctoral thesis
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