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Hiroshi Naraoka Last modified date:2016.09.17

Professor / Material Science of Solar Planets
Department of Earth and Planetary Sciences
Faculty of Sciences

Graduate School
Undergraduate School

The research center for Planetary Trace Organic Compounds (PTOC) is aimed to study trace organic compounds under the extremely clean conditions for the understanding of chemical evolution in the universe. The PTOC center was founded on 2016, and supported by Grant-in-Aid for Scientific Research (S) of Japan Society for the Promotion of Science (JSPS) and Kyushu University. .
Homepage in English (Research and Teaching) .
Academic Degree
Doctor of Science
Field of Specialization
Organic Cosmogeochemistry
Outline Activities
The Earth environment has changed dynamically since its birth. In particular, biological activities have important roles on the evolution of the Earth's surface environment. In order to understand better the environmental changes and associated biological acitivities, we should study geochemical cycles of elements and molecules that operate in Earth's surface system over different periods of time. Furthermore, origin of life on the Earth is the most challenging issue in science. Past biological activities as well as chemical evolution prior to life should be studied by organic compounds in rocks (chemical fossils known as biomarkers) as well as extraterrestrial materials such as meteorites. My recent research projects include: 1) characterization of organic matter in carbonaceous chondrites; 2) chemical and isotopic studies of sedimentary organic matters from Archean to present to clarify biological activities associated closely with Earth’s surface changes; 3) multi-isotope studies of biomarkers in deep-sea drilling samples as well as hydrothermal environments to investigate bacterial communities with their metabolisms; 4) modern geochemical cycles of organic matter in terrestrial-marine systems including isotopic characterization of bioorganic compounds; 5) laboratory simulation in formation and isotope fractionation of organic compounds; and 6) development of molecular and isotopic analytical techniques for trace amounts of organic matter in natural samples.
Research Interests
  • 1. Chemical evolution of organic compounds in extraterrestrial materials
    2. Origins of life on the earth and the evolution of the biosphere
    3. Biogeochemistry of sediments and sedimentary rocks, and biogeochemical cycles on the earth
    4. Stable isotope geochemistry of organic compounds in natural environments
    keyword : Meteorite, Chemical evolution, Origins of life, Evolution of Earth's environment, Biomarker, Lifes in extreme environments, Stable isotopes
Academic Activities
Membership in Academic Society
  • The Geochemical Society
  • The Meteoritical Society
  • International Society for the Study of Origins of Life
  • European Association of Organic Geochemists
  • American Geophysical Union
  • The Japanese Society for Planetary Sciences
  • The Society for the Study of the Origin and Evolution of Life JAPAN
  • The Geochemical Society of Japan
  • The Japanese Association of Organic Geochemists
  • Japan Geoscience Union