• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.57.4-58
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• 2021

Asteroids have undergone various processes such as impacts, space weathering, and thermal evolution. Because they expose their surfaces to space without atmosphere, these evolutional processes have been recorded directly on their surfaces. The remote-sensing observations have been conducted to reveal these evolutional histories of the target asteroids. For example, crater and boulder distributions are unambiguous evidence for past nondestructive impacts with other celestial bodies. Multiband and spectroscopic observations have revealed space-weathering history (as well as compositions). Whereas most physical quantities have been examined intensively using spacecraft and telescopes, only a little has been studied on "the grain size". It is one of the fundamental physical quantities for diagnosing the collisional and thermal history of asteroids. Our group has conducted polarimetric research of asteroids (as well as Moon [1]) to determine the particle size and further investigate the evolutional histories of target asteroids [2],[3]. For example, the existence of regolith on an S-type asteroid, Toutatis, was suggested almost twenty years before space exploration [4]. Moreover, we reported that near-Sun asteroids indicate a signature of submillimeter grains, which could be created by a thermal sintering process by solar radiation [5]. However, it is important to note that in-situ polarimetry has not been reported on the asteroid surface, although the Korean Lunar Exploration Program aims to do polarimetry on the lunar surface [6]. Therefore, it is expected that the polarizer mounted on the Korean Apophis spacecraft can make the first estimate of the grain size and its regional variation over the Apophis surface. In this presentation, we outline research of S-type asteroid surfaces through remote-sensing observations and consider the role of polarimetry. Based on this review, we consider the purpose, potentiality, and strategy of the polarimetry using the onboard device for the Apophis spacecraft. We will report a possible polarization phase curve of Apophis estimated from ordinary chondrites and past observational data of S-type asteroids, taking account of the space weathering effect. Based on this estimation, we will consider the strategy of how to determine the particle size (and space weathering degree) of the Apophis surface. We will also mention the detectability of dust hovering on the surface.

• Sim-seong Yeon-gu
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• v.27 no.1_2
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• pp.1-27
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• 2012

It aims to deal with a topic of coniunctio oppositorum, hieros gamos in a Korean fairytale <Gurungdungdung Sin Seonbi>, in which a human heroine was marrying an animal husband. This Korean fairytale may be compared with Greek mythology <Eros and Psyche> introduced by Apuleius and <Dassingende springende Löweneckerchen> collected by Grimm Brothers. All these fairytales commonly tell that animal husband figures have divine nature. Because animals live their lives totally obeying instincts, the collective unconscious principles of species are completely accomplished. The animal nature excludes ecocentric attitude so that it has transpersonal divinity. The hero is transformed into an animal in the fairytales, which will provide an opportunity to change a one-sided exaggerated attitude of the ego consciousness and acquire universal humanity. During being an animal, the hero would have experienceds to recognize true meaning and value of other living creatures in nature and have attained wisdom of nature. The animal is a symbolic being who will realize value of collective and universal life so as to act therapeutically and contribute to the total personality, individuation processes. Animals in the fairytales correspond to the compensatory contents of the unconscious. Animal figure itself is opposite to the ego consciousness itself because the ego understands the unconscious contents like animal figures have instinctual impulse that the ego will not accept at all. Coniunctio oppositorum in the fairytales is going to show the ego's rendezvous processes to meet the unconscious. The fact that the hero turns into an animal or marries animal partner is a psychic event which greatly lowers under the level of ego consciousness. To overcome the state, it is essential for the hero to regain humanity or to transform animal partner into a human being. By the recovery of humanity or reaching the human level, compensation of the unconscious can be realized in the conscious life. In a Korean fairytale <Gurungdungdung Sin Seonbi>, male partner is a serpent but the heroine marries the serpent and make it cast off skin. Over sufferings and complishment of several tasks, heroine truly meets her husband. In this processes, the heroine obtains divinity. As result, her marriage to animal husband means hieros gamos. In this fairytale, we will be able to look through the ways how female ego-consciousness to make relations to the unconscious and to fulfill individuation.