• Title/Summary/Keyword: near-earth object

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Near-infrared polarimetric study of near-Earth object 252P/LINEAR: An implication of scattered light from the evolved dust particles

  • Kwon, Yuna G.;Ishiguro, Masateru;Kwon, Jungmi;Kuroda, Daisuke;Im, Myungshin;Choi, Changsu;Tamura, Motohide;Nagayama, Takahiro;Kawai, Nobuyuki;Watanabe, Jun-Ichi
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.2
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    • pp.44.2-44.2
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    • 2019
  • Comets, one of the least-altered leftovers from the nascent solar system, have probably preserved the primitive structure inside, whereas their surfaces become modified from the initial states after repetitive orbital revolutions around the Sun. Resurfacing makes the surface drier and more consolidated than the bulk nuclei, creating inert refractory dust layer ("dust mantle"). Near-infrared (NIR; 1.25-2.25 m) polarimetry is theoretically expected to maximize contrast of the porosity between inner fresh and evolved dust particles, by harboring more dust constituents in the single wavelength than the optical; thus, intensifies electromagnetic interaction in dust aggregates. Despite such an advantage, only a few studies have been made in this approach mainly due to the limited accessibility of available facilities. Herein, we present our new multi-band NIR polarimetric study of near-Earth object 252P/LINEAR over 12 days near perihelion, together with the results of optical (0.48-0.80m) imaging observations and backward dynamical simulation of the comet. Based on the results, we will characterize the dust properties of the comet and discuss the possible environmental (temperature and UV radiation) effects that could produce the observed phenomena.

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THE PROSPECT OF INTERSTELLAR OBJECT EXPLORATIONS FOR SEARCHING LIFE IN COSMOS (우주생명현상과 성간천체 탐사 전망)

  • Minsun Kim;Ryun Young Kwon;Thiem Hoang;Sungwook E. Hong
    • Publications of The Korean Astronomical Society
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    • v.38 no.2
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    • pp.25-36
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    • 2023
  • Since interstellar objects like 1I/'Oumuamua and 2I/Borisov originate from exoplanetary systems, even if we do not visit the exoplanetary systems, flyby, rendezvous, and sample return missions of interstellar objects can provide clues to solve the mysteries of cosmic life phenomena such as the origin of exoplanetary systems, galactic evolution, biosignatures (or even technosignatures), and panspermia. In this paper, we review space missions for interstellar object exploration in the stage of mission design or concept study such as Project Lyra, Bridge, Comet Interceptors, and LightcraftTM. We also review space missions, OSIRIS-REx and NEA Scout, designed for Near Earth Asteroids(NEA) explorations, to investigate the current state of basic technologies that can be extended to explore interstellar objects in a velocity of ~ 6AU/year. One of the technologies that needs to be developed for interstellar object exploration is a spacecraft propulsion method such as solar sail, which can catch up with the fast speed of interstellar objects. If this kind of propulsion becomes practical for space explorations, interstellar object explorations will mark a new era and serve as a driving force to provide evidences of cosmic life.