How did the planets, comets and meteorites form in the solar nebula? I want to answer the question in view of laboratory experiments. Although it is impossible to prepare the duplicate environment of solar nebula, I am seeking the clues of the answer from the smoke experiments in laboratory.

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Using a high-power laser, Gekko XII, at Institute of Laser Engineering, Osaka University, we carried out a acceleration experiment of projectiles. We observed the acceleration of glass spheres with a diameter of 100 micro-meters. The glass spheres were accelerated to ~ 13 km/s. Also, we observe a CaO line in the spectrum of self-luminous impact vapor.

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M. Yanagisawa and H. Ikegami (Univ. Electro-Communications, Tokyo, Japan), Impact flash efficiency in the high-velocity impact of porous materials: High-velocity impacts generate optical radiation (impact flash), and the optical energy divided by the kinetic energy of projectile is called "optical efficiency". We show that the efficiency is higher for porous projectile than for solid projectile in a preliminary one-dimensional collision model. We also speak about the laboratory experiments to confirm the higher efficiency for the porous projectile.

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Post shock temperature of water ice is one of the most important heat sources for the accretional heating of ice bodies and the viscous relaxation of impact craters. Therefore we conducted impact experiments of water ice and measured the post shock temperature of impact crater by using an infrared video camera. According to the obtained temperature profiles, we estimated the ratio of the thermal energy deposited in the crater to the projectile kinetic energy, which corresponds the efficiency of the energy conversion from the projectile kinetic energy to the irreversible heat. As a results, we found that about 10% of the projectile kinetic energy was partitioned into the post shock heating of the impact crater.

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Collision between solid bodies at low velocity regime is one of the most important elementary processes in the planetary formation or in the Saturn's ring particles collision.In our previous study, we performed low velocity collision experiments of gypsum spheres of about 50% in porosity.We found that compaction occurred at lower velocities than those where fragmentation fracturing occurred and the compaction reduced the value of restitution coefficient.We prepared gypsum spheres with porosity was higher than the previous ones in order to compare the degree of compaction and the effect of the porosity on the restitution coefficient.We quantitatively estimated the fraction of the energy partitioned to the compaction process, tangential velocity and rotational motion of the sphere after the impact and investigated the effects on the value of restitution coefficient.

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We have studied the effects of target material properties on diameter growth of crater cavity by using the laser method. In our previous studies, we found that (1) the increase rate in the diameter growth follows a power-law relation at early times during the excavation process, but the increase rate at late stages deviates from the power-law relation; (2) the power-law exponent and the degree of deviation from the power-law depends on target materials. In this study, we discuss how the power-law exponent and the degree of deviation depend on target properties. We did impact experiments for water targets as well as soda-lime glass spheres with various grain sizes and dry sand, and determined the power-law exponent and the degree of deviation for these targets. Based on these results, we discuss the effects of target material properties on a scaling relation of impact cratering in the gravity regime.

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In order to clarify the ice flow features found on the icy satellites and Mars, we carried out the deformation experiments of ice-solid particles mixture systematically to study the effects of solid particles. The sample was prepared with the mass content of solid particles, 50, 70, and 80 wt.%, and examined the relationship between the content and the effective viscosity. Furthermore, we used three types of solid particles, and examined the dependence of the viscosity on the types of the particles. As a result, in the case of 1 micron-m silica beads and serpentine powder, the viscosity increased with increasing the content. On the other hand, in the case of 1mm glass beads, the viscosity decreased with increasing the content.

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Lunar surface heat flow values were measured directly during the Apollo missions. In this measurement, temperature gradient and thermal conductivity was obtained by using independent method. Recently, temperature gradient in the lunar regolith was revised to be about 25% of previous value. However, the value of thermal conductivity obtained by in-situ measurement has never re-analyzed. In this presentation, we show that the results of re-analysis.

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Lunar earth quake called Moonquake had been observed by Apollo missions. This experiment was carried out in a part of the ALSEP (Apollo Lunar Surface Experiments Package) of Apollo 12, 14, 15, 16. Network observation by using the all stations was carried out for about five years until September 30, 1977. On the other hands, Lunar Surface Gravimeter (LSG) experiment was carried out at Apollo 17 in order to detect the gravitational wave and measure tidal deformation of the Moon. This experiment has never obtained meaningful data for gravity, however, the instrument had been functioned as seismometer. We analyzed the data obtained by LSG in order to discuss lunar interior. Here, we show that the the quality of the LSG data and the results of first analysis.

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The lunar shallow structure is a key to clarify local geological feature and to construct lunar base and utilizing resources (such as regolith). Past direct exploration of lunar shallow structure is mainly conducted by Apollo program. In this program, some experiments using artificial moonquake has been conducted. However, most of data used determining internal structure of the moon has relied on natural moonquakes, and these data has major problem such as data quality. Therefore, we now propose the possibility of the mission detecting shallow structure of the moon using artificial moonquake for obtaining basic data for future construction of the lunar base and utilization of regolith. We will present some proposals of mission of lunar shallow structure using lunar seismic waves suitable for unmanned exploration after SELENE program and primary manned mission phase.

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We have examined the integrated science of the Moon using KAGUYA (SELENE). The strategy is summarized as: 1) drawing two-dimensional maps to integrate various geologic units into a coherent map, 2) drawing three-dimensional maps of subsurface structures beneath maria and highlands, 3) joint studies of special topics such as mare tectonics and crustal formation, 4) joint studies of advanced topics such as dichotomy and bulk composition. Using the strategy, we will shed light on the tectonics of maria; crustal formation; explorations of polar regions; inner structure of multi-ring crater - Orientale; and lunar environments to figure out the origin and evolution of the Moon.

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KAGUYA (SELENE) is a Japanese lunar mission which will be launched using H-IIA vehicle in September 2007 by JAXA. We are planning to improve lunar gravity field model by four-way Doppler measurements and differential VLBI observations using three orbiters of KAGUYA (SELENE) mission. KAGUYA is composed of the main orbiter and two small free-flyer subsatellites, i.e., the Relay Satellite (Rstar) and the VLBI Radio Satellite (Vstar). Each subsatellite weighs approximately 50kg.

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The SELENE will carry an optical instrument called Lunar Imager/Spectrometer (LISM). The LISM consists of three optical sub-instruments: the Terrain Camera (TC), the Multi-band Imager (MI), and the Spectral Profiler (SP). LISM will provide the data for scientific knowledge and possible utilization of the Moon. In this presentation, we will introduce the LISM operation plan with the planned SELENE orbit.

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The Multiband Imager (MI) is one of the 14 instruments for the Japanese SELENE (KAGUYA) mission that will be launched in 2007. MI shares some components and electronics with other two instruments which are the Terrain Camera (TC) and the Spectral Profiler (SP). The 3 instruments (MI, TC and SP) are called as the Lunar Imager/ SpectroMeter (LISM). MI is a high-resolution multiband imaging camera consisting of visible and near-infrared sensors which have 5 visible and 4 near-infrared bands. We are going to observe the global mineral distribution of the lunar surface in nine band images of MI. LISM team members have been discussed about research plans using LISM data and number of proposed research topics in 3 instruments total became around 80. Within them number of research topics in which MI data is used mostly are around 40. Example of such MI research topics are, investigation of small but scientifically very important areas such as crater central peaks and crater walls, understanding of evolution history of the mare region and understanding of chemical compositional distribution within highland terrain.

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Lunar reflectance data is useful not only for lithorogical identification of lunar surface but for radiometric calibration and determination of exposure time for optical sensors of lunar probe. To gain lunar reflectance, multi-band images of the lunar surface and those of some standard stars had been acquired with a liquid-crystal tunable filter (LCTF) telescope at the peak of Mt. Haleakala (Hawaii, USA) at 5 bands (650, 750, 900, 950, and 1000 nm) by the members of Advanced Lunar Imaging Spectrometer (ALIS) project. LCTF telescope is a multi-band tele-scope using a tunable liquid-crystal filter covering 650 - 1100 nm. It is composed of a refract-ing telescope (Vixen, ED80S) equipped with a cooling CCD camera (Apogee, U260) and a tunable liquid-crystal filter (Cambridge Res. Inc., NIR-07). Obtained data indicates that the reflectance data of Clementine UVVIS is too high. The reflectance value of Clementine is about 60 – 70 % brighter than our new data. The lunar reflectance images, the software tools, and the raw data are open to public at my web site. This study reports the method of deriving the lunar reflectance images from the observed images and the ideas for applying the data to lithorogical identification, exposure determination, etc.

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The lunar surface TiO₂ map helps us understanding the process of the lunar mare formation. Therefore, the lunar surface TiO₂ map has been made by several scientists using the characteristics of the ilmenite spectrum, which are dark at 300 nm-2600 nm wavelength region and the reflectance at 415 nm and 750 nm are comparable. Ilmenite is the dominant carrier of the Ti at the lunar surface. To make the lunar surface TiO₂ map, therefore, we can use the ilmenite spectrum instead. In this work, we have not found the ilmenite absorption band around 500 nm at visible wavelength band. And the lunar surface TiO₂ abundance can be estimated accurately by using the smaller size reflectance. Counting these results, we might be able to establish the new methods to estimate TiO₂ abundance on the lunar surface.

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While source regions for lunar meteorites are generally unspecified unlike Apollo returned samples, they likely represent random sampling of the global lunar surface. Source craters/sites can be specified only for lunar meteorites with extremely chemical compositions, coupled with isotopic ages of basalt formation, impact events, and ejection from the Moon. The detailed knowledge of the lunar meteorites enables us to identify the source regions, with the aid of the global elemental distribution map based on the remote-sensing data. Such source-identified lunar meteorites are of great importance not only in providing the geologic information of the unexplored regions, but in serving as "ground truth" for the specific sites which can be utilized for calibration of the orbital data. We report the lunar meteorites with the identified source craters/sites, which will be major science targets to be studied with KAGUYA data.

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It is very useful to select lunar features by query not only on a region but on land names. However, there are no any convenient system that searches lunar features from lunar names in domestic and overseas system. Therefore, we are starting construction of lunar nomenclature search system based on QBO (Query-By-Object) approach. Using this method, we can designate specific points of the moon using nearby name by lunar feature names. Currently, we are focusing on the region including Copernicus crater. In this lecture, we report our progress and future strategy.

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To simulate the evolution of amorphous Mg2SiO4 (forsterite) to the forsterite crystals, we need amorphous particles in the experiment as the starting materials. Although amorphous forsterite has been synthesized from vapor phase, these particles are too small (< 1 μm) to be investigated by optical method. Therefore, we have applied a gas jet levitator method to solve this problem. A gas jet levitator method is useful to avoid heterogeneous nucleation during cooling process and thus melt droplets were very stable at large supercooling (> 1000 K).The starting materials were synthesized forsterite spherules (~ 2 mm), which was set at the top of the nozzle (1 mm in diameter) of the gas jet levitator and then levitated by introducing Ar gas. The spherule was melted by CO2 laser (100 W) irradiation. The melt temperature was measured with a pyrometer.The experimental results show that amorphous formation of forsterite took place at ~ 1000 K with a larger cooling rate than 300K/s, which was much smaller cooling rate as obtained by Tangeman et al. (2001), 700 K/s. While, enstatite melts with higher SiO2 content formed only amorphous material at any conditions.

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Under a levitated environment, it is predicted that the crystallization of totally melted droplets would be difficult, because of the requirement of the nucleation process. Therefore, nucleation rate of chondrule melts is also thought to be difficult. We investigate the nucleation rate of Mg-silicate, which is main component of the chondrules, by using a gas-jet levitator.Starting materials are spherules (= 2-3 mm). We prepared pellets of powdered reagents of MgO and SiO2 mixed with MgO/SiO2 mol of 1.0 (enstatite)-2.0 (forsterite). The gas-jet levitator (Nagashima et al., 2006) consists of an aluminum diffuser and an inlet for the argon gas jet (10 m/s).During the cooling process, the forsterite melt set on the graphite rod did crystallize at very small supercooling (dT = 50 K). In contrast, the levitated forsterite melt also showed crystallization, but at larger supercooling (dT > 1000 K). And spontaneous crystallization from levitated chondrule melts is very difficult and the "almost chondrules" should turn into glass in spite of the slow cooling. Therefore, the crystallization of chondrules might occur by collisions with cosmic dusts.

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In the stage of chondrule formation in the protoplanetary disk, smaller grains would reach the melting point earlier and could vaporize while larger grains are in the process of melting. In this study, we examine the process of condensation, especially competition between homogeneous nucleation and formation of core-mantle type grains due to heterogeneous nucleation. We obtained an analytic expression of the condition to form new dust grains by the homogeneous nucleation. The condition gives a new constraint on the mechanism of chondrule formation.

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Separation of iron globules from chondrules during chondrule formation process is investigated kinematically. The results of calculation show that if those iron globules were initially inside and transported to the surface of the chondrule, most of them would be expelled from inside to outside due to the surface tension force. The results show a possibility that this process may be responsible for the depletion of siderophile elements in natural chondrules.

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We carried out reaction experiments between forsterite and Si-rich gas using molecular beam epitaxy in order to study formation of enstatite under circumstellar conditions. The reaction product was probably amorphous SiO, indicating the difficulty of enstatite formation in stellar winds.

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We could find matrix olivine particles with various morphologies and surface microtopographs in primitive meteorites like Allende chondrite. We have experimentally tried to reproduce the morphologies and surface microtopographs of the matrix olivine with condensation experiments.
A 100W of CO2 laser was employed to heat a forsterite polycrytalline spherule for melting in <100 sec. The condensed forsterite crystals were characterized by TEM, FE-SEM, AFM and DICM.
As the temperature decreased and thus the supersaturation of the vapor increased, the morphology of forsterite changed from a bulky type to a platy type, then to a columnar needle shape, and finally to a droplet type. Various 2-dimentional islands with the step height of 0.3 nm-few nm were observed: rectangular growth islands with a smooth-edge step, islands with a rough-edge step, and a droplet type. These external and surface morphologies have been compared with natural matrix olivine. In addition, we could find matrix olivine particles with various surface microtopographs, which show that the particle formed at 1800 K followed by rapid cooling in ~10 s down to 1000 K.

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The concentrations and isotopic ratios of Li in chondrule-forming minerals from the Allende meteorite were measured with SIMS. The olivines are Li-depleted (<0.1 ppm) , and the ranges and the mean abundance of Li are different from each individual chondrule. There is no Li-zoning structure of the abundances and the isotopic compositions of Li. The maximum diffusion distance of Li within olivines can be estimated to be less than 70 micrometers. The Li-compositional heterogeneities in most chondrule olivines are about several tens micrometers, therefore chondrules in the Allende meteorite may preserve the original distribution of Li after solidification of chondrules.

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CI, CM, CR and TL chondrites experienced strong aqueous alterations on their parent bodies. Therefore, a study of the alteration process is important for understanding the evolution of early solar system materials. To investigate the aqueous alteration process, many hydrothermal alteration experiments have been performed so far using crystalline silicates or chondrites themselves as starting materials. In contrast, silicates in interstellar medium and molecular cloud are considered to be amorphous based on IR astronomical observations. Therefore, to understand the aqueous alteration process of amorphous silicates, we have carried out hydrothermal alteration experiments of amorphous silicates with the Fe- and S-free CI composition. The amorphous silicates were heated at 650-750^oC to prepare additional starting materials with different degree of olivine contents. A mixture of the starting material and deionized water (or acid/alkali solutions) was heated at 100-200^oC for 24-336 hrs. Run products were analyzed using XRD, SEM-EDX and micro-IR spectroscopy. Saponite, serpentine, talc and calcite were easily formed from the starting materials including amorphous silicates.

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I studied mineralogy and petrology of lherzolitic shergottites and showed their crystallization history. It is most likely that all samples of this group originated from a common igneous body located near the Martian surface. Especially, RBT04262, a new sample recently discovered, contains small amounts of cumulus phases compared to previously known lherzolitic shergottites, suggesting that it was located at the upper region of the igneous body. Because of the presence of RBT04262 showing a basaltic texture, it is not appropriate to call this group as "lherzolitic".

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Observations of the asteroid Itokawa by the HAYABUSA spacecraft revealed that the asteroid has a rubble-pile structure and holds large porosity. We detailedly discuss a possible internal structure of the asteroid.

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Fragments can be simply modeled as triaxial ellipsoids with axis lengths a, b, c, such that their shapes are described by the axial ratios b/a and c/a. Some laboratory experiments of catastrophic disruptions showed that the distributions of the fragment axial ratios b/a and c/a are peaked at values close 0.7 and 0.5, respectively. In this study, the shapes of boulders on asteroid Itokawa are measured from the images of spacecraft Hayabusa in order to investigate whether these shapes resemble the shapes of the fragments.

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Micrometeorites (MMs) of likely cometary origin have been discovered in Antarctic ice and snow. The porosities and fractal dimensions of MMs would provide clues about dust evolution in the early stages of the solar system. Using X-ray microtomography, we investigate 3-D structures of MMs recovered from Antarctic snow. The samples were imaged at beamline BL20XU and BL47XU in SPring-8 (10keV, voxel size: 500nm). Most of pores in the MMs are connected to their exteriors (i.e., open pores). We have developed a new method to extract open pores and to obtain effective porosities, P, of the samples. Their fractal dimensions, D, are also obtained using a box counting method. Our analysis shows that P of porous MMs decreases with increasing D. The same method is applied to examine 3-D structures of model aggregates made by simulation of collisions between dust aggregates (Wada et al., 2007). With increasing the collision velocity D increases, while P decreases first, increases and finally decreases again. The D-P relation apparently shows a link between the MMs and the model aggregates. The MMs might preserve information on dust aggregation and accumulation processes, despite of subsequent alterations of the dust such as compaction in comets and heating during atmospheric entry.

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We report our preliminary results in search of interstellar organic grains in meteorites using the nanosims.

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Cometary dust is composed of a mixture of silicates, sulfides, metals, and organics. Although the organic material is the most abundant component, there is no consensus as to its composition. An estimate of the absorption coefficient for an analogue organic sample varies from one experiment to another. Using the discrete-dipole approximation, we study how light scattering by agglomerated debris particles depend on the imaginary part of refractive index Im(m) in the range from 0 to 1.3. We fix the real part of the refractive index Re(m)=1.5 and consider the size parameters x=5, 10, and 20. We found that Umov's law is valid in both metallic and dielectric domains, but not in the transition regime. The phase angle of the maximum polarization almost monotonically increases with Im(m). Non-absorbing particles reveal a deep branch of negative polarization at small phase angles. Particles with Im(m) ~ 0.2 have no negative polarization, but large particles with Im(m) ~ 1 exhibit the negative polarization. By comparing our results with observations of comets, we can constrain the imaginary part of refractive index for organics in cometary dust.

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A coma of a long-period comet often exhibits infrared spectral features of forsterite, while comet formation took place in the outer solar nebula where the temperature is too low for amorphous silicates to crystallize. The origin of forsterite provides a clue to better understand the environment of the comet formation region and thus a link between comets and planetesimals. Here we explore the origin of forsterite in cometary dust by comparing the observed forsteritic features with the calculated absorption cross sections for our model dust aggregates.

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Evaporation experiments of forsterite in hydrogen gas were carried out in order to understand shape change of forsterite particles due to anisotropy of evaporation and its effect on infrared spectroscopy. The infrared spectrum of forsterite in HD100546 (a PP-disk) can be explained by a disk-shaped forsterite elongated to the a- and b- axes, and our experimental results indicate that such grains can be formed by anisotoropy evaporation of forsterite in hydrogen gas.

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Cometary dust of Wild2 was recovered by NASA Stardust mission. Tracks were made in aerogel by impacting particles at hyper velocity of 6.1 km/s. Variety of the impact tracks shows variety of materials composed of the cosmic dust. Among these tracks, tracks with unique shapes, such as curved and spiral tracks can be recognized. If a spiral track with a pitch of about 1.5 mm was formed by spinning of an impacting particle, this particle must rotate at about 4 million rps. In this study, 3-D structures of two tracks (C2017,2,100,0 A and B), which seem to be spiral under an optical microscope, were obtained by microtomography. Imaging experiments were performed at BL47XU of SPring-8 at 8 keV with 3600 projections and voxel size of 1.05 microns, which gives the effective spatial resolution of about a few microns. Track cavity, condensed aerogel and individual particles were recognized in CT images, and their 3-D distributions were obtained. The spiral features correspond to cracks, which develop outwards from the track walls. However, the spiral cracks develop only partially. This strongly suggests that the hypervelocity rotation was not responsible for the spiral features. Heterogeneity of the aerogel may cause the spiral features.

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Stardust spacecraft of NASA captured cosmic dusts from Comet Wild2, but the particles captured in aerogel were disaggregated into many grains. There were a variety of morphologies of the hypervelosity impact tracks, suggesting a variety of the cosmic dust. We tried to estimate physics of the capture in silica aerogel based on three-dimensional structures of impact tracks obtained from X-ray computed tomography (CT) and XRF.

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Jupiter, Saturn and most of more than 200 extrasolar planets in the past decade are gas giant planets. Their interior structures are still poorly known. This is because the current uncertainties in their interiors are due to the three following factors; heat transfer, observational precisions and equations of state for materials, especially hydrogen and helium, under high pressure and temperature.
We considered the three factors as the differences in mechanisms of heat transfer, errors in observational properties and models for equation of state and then investigated their effects on interior structures of Jupiter and Saturn systematically.

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We have been discussing a Jovian mission in 2020's under the cooperation between Europe and Japan. It is the same framework as Mercury mission BepiColombo. The proposed mission involves two Jovian orbiters and one satellite orbiter.

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Recently free oscillations of the earth have been reported to be continuously excited in the absence of great earthquakes. Average amplitudes of those modes are about 0.5 nano gal in the mHz band and the amplitudes vary annually or semi-annually about 15%. Modes at frequencies of 3.7, 4.4, 5.1 and 6.1 mHz have remarkable excess in amplitudes. At those frequencies, the seismic Rayleigh branch is crossing over the infrasound branches of the atmosphere. To explain those excess, we calculated the Rayleigh modes and the acoustic modes in mHz band to examine the effect of atmospheric structure on the normal modes. We found that the excess amplitudes of the modes at the branch crossings can be reproduced only in the case that the excitation source is at the bottom of the atmosphere. These results show that the atmosphere plays an important role in the excitation of the observed background free oscillations.

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We developed a numerical model to study the hydrodynamic escape of neutral gas from planetary atmospheres by solving the time-dependent multi-component hydrodynamic equations. Hydrodynamic escape of hydrogen from a planetary atmosphere can remove heavier gases, which can be dragged along with the escaping hydrogen. Application of the developed numerical code to hypothetical episodes of hydrodynamic escape from Venus could solve the following problems: (1) substantial quantities of water may have been lost without the need to oxidize large amounts of the crust, (2) Ar and Ne isotope ratios indicate that Venus lost little or no Ar and 50% or less of its original complement of Ne. We focus the loss mechanism of Venusian water by the photo-dissociation of water vapor in the upper atmosphere, followed by the escape of hydrogen and dragged oxygen to space. And we discuss the effect of infrared cooling by CO, which may radiate away EUV energy that slow the speed of hydrodynamic flow. It would therefore be expected that some loss of Ne occurred, but that no loss of the heavier Ar took place.

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Previous studies proposed that the Titan's N2 atmosphere is produced by the pyrolysis of NH3 by impact shock heating. However, results of our numerical model found that N2 atmosphere cannot be formed by the impact in the CH4-NH3 atmosphere which previous studies treated. Thus this study conducts numerical simulations for various impact conditions, such as atmospheric composition and impact velocity, and reconsiders conditions in which the N2 atmosphere is formed by impacts.

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For the purpose of investigating fundamental features of thermal convection in the Martian atmosphere, a three-dimensional non-hydrostatic model for the Martian atmosphere is developed and a numerical simulation is performed. The governing equations of the model are based on the quasi-compressible system. The turbulent mixing coefficient is calculated by using a prognostic equation ofsubgrid scale turbulent energy and the surface flux is estimated by using bulk method. As a preliminary experiment, convection is generated by horizontally uniform heating whose profile is given from a result of a one-dimensional radiative convective equilibrium model. The convective field which can be regarded to be in a statically equilibrium state is examined.

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For the purpose of performing comprehensive numerical experiments on various moist atmospheres including terrestrial and Jovian atmospheres, an atmospheric general circulation model flexible in changing program codes is designed and implemented. It is often necessary to exchange numerical schemes of indeterminate physical processes such as cumulus process. In order to facilitate those exchanges, (1) a general design for physical process modules with initializing routines is presented, (2) a standard procedure for testing each physical process is presented and a common library for constructing test programs is developed.

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Orbital elements such as semi-major axis, eccentricity and obliquity have a great influence on planetary climate through the change of the insolation. Extra-solar planets detected so far have various values of orbital elements, so it is very important to know the effects of them on the climate of planets if one wants to explore the possibility of life outside the earth. We had studied the relation between the orbital elements and the planetary climate using latitudinally one-dimensional energy balance model (EBM). This time, we will check the EBM results using atmospheric general circulation model as a more realistic one, and from the differences and detailed mechanisms, we will discuss what kind of influence orbital elements may have on the habitable environment.

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Extrasolar planets near stars is considered to rotatesynchronously due to strong tidal force. On a synchronously rotating planet, one side is permanentlyilluminated while the other side is in perpetual darkness. Joshi et al. (1997) performs an atmospheric GCM simulation on a synchronouslyrotating planet, but their model does not contain hydrologic processes. In this study, a GCM experiment is performed fora moist atmosphere on a synchronously rotating planet, and atmospheric circulation and heat transport are examined. The results indicate thatlongitudinal heat transport in the low latitudinal region is caused by propagation of equatorial Kelvin and Rossby waves,and that in the higher latitudinal regionis caused by baroclinic eddies.

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The transit method is one of the ways of detecting Extra-Solar planets. Even small telescopes can be applied to this method, and the obtained results provide us various parameters of planets when we combined by the Doppler shift method.
The 50cm telescope in the Mitaka campus of National Astronomical Observatory of Japan (NAOJ) is used to observe the extra solar planetary systems detected by the N2K Consortium as the candidates of the transit objects. In this poster paper, we report our research outline together with the results of the analysis of our observations performed until now.

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We develop an observation system for the extrasolar planets by using the transit method and perform verification experiments of the system in cooperation with the municipal Kihara observatory in Nayoro City, Hokkaido. Advantage of public observatories is to keep relatively long observation time of the telescopes than those belong to major research institutes. We constructed the observation system with equipments of both organizations. As a verification experiment of this system, we observed a extrasolar planet TrES-1_b to which the planet parameter and the date of transit were well-known. The results show that the time evolution of the magnitude of the fixed star is consistent to the previous study (Alonso et al., 2004) by using same observation method.

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A transit of an extrasolar planet is a phenomenon that it cut across in front of its parent star. The detections of the phenomenon tell about the planet, such as its mass and density. We have been searching for the extrasolar planet candidates by transit method with the Kiso-Schmidt telescope from 2005. Wide field accurate photometric monitoring is necessary for successful planets detection using the transit method. The Kiso-Schmidt telescope has enough prerequisite because it has a wide field view (50'x 50'). We got about 3,000 lightcurves so far and detected near 50 variable star candidates. We present details and results of this observation.

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Astronomical observation has revealed the presence of crystalline silicates around both evolved and young stars and comets. Circumstellar crystalline silicate grains can be formed by annealing of amorphous grains. Silicate crystals, such as olivine and pyroxene, should grow anisotropically along different crystal axes with different rates.We have performed crystallization experiments of synthetic amorphous silicate materials in laboratory and measured their infrared absorption spectra. By comparison with the spectra with those calculated for crystalline silicate spheroids with different crystallographic orientations, we discuss the effect of anisotropic crystals on their infrared spectra.

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C/2006 M4 (SWAN) became 2 magnitude brighter than the prediction that with magnitude of about 6 during from October end to November beginning. We took the comet images on 5 bands (B, V, Rc, Ic, and No filter) that used by cooled CCD camera (SBIG STL-1001E) by direct focus of 15cm refracting telescope (f.l.1800mm) in Himeji City "Hoshinoko Yakata". From comparison of each images, the usually blue ion tail included red light by probably H₂O⁺ ion tail. From comparison of images and the calculation by Beseel-Bredichin theory, the dust tail made by dust particles that was released in those days of the perihelion passage.

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