A great number of experiments have been done to examine possible prebiotic formation of bioorganic compounds such as amino acids in possible primitive environments. There are two scenario of prebiotic formation of bioorganic compounds: An endogenous formation scenario and an exogenous formation scenario. The latter scenario was supported by the facts that a wide variety of organic compounds were detected in meteorites and comets. It is now suggested that organic compounds in extraterrestrial bodies were originally formed in extremely cold environments such as in molecular clouds. Laboratory experiments showed that complex precursors of amino acids could be formed from simulated interstellar media by irradiation with high-energy particles. It was suggested that such extraterrestrial organic compounds were delivered mainly by cosmic dusts. We have, however, very limited information on organic compounds in cosmic dusts since they are captured within terrestrial environments. We proposed a novel astrobiology mission “Tanpopo” by utilizing the international space station. In the mission, cosmic dusts will be collected with ultra-low-density aerogel, and organic compounds in them will be analyzed. In the mission, organic compounds simulating extraterrestrial organics will be directly exposed to solar ultraviolet light and cosmic rays at the same time to study the fate of organic compounds in cosmic dusts near the Earth orbit.
Analyses of organic compounds in the extraterrestrial materials, e. g. carbonaceous chondrites, micrometeorites, and cometary dust, are important for the study of origins of life on the Earth, since the terrestrial living organisms are formed by highly organized organic compounds and, organic compounds and their source materials should be transported into the Earth from the outside of the Earth. To avoid the contaminants from the terrestrial organisms is the most important for organic analyses of the extraterrestrial materials. Therefore, intact micrometeoroids captured on the exposure facility of the “Kibo” module at the International Space Station by “TANPOPO” mission are suitable for the astrobiological studies concerning with origins of life. In this review, organic analyses of extraterrestrial materials are summarized and tasks for the analyses of organic compounds in the sub-mm sized micrometeoroids, especially captured particles in the “TANPOPO” mission, are described.