翻訳と辞書 Words near each other ・ Exploration Flight Test 1 ・ Exploration Gateway Platform ・ Exploration geology ・ Exploration geophysics ・ Exploration in Europe ・ Exploration logging ・ Exploration Mission 1 ・ Exploration Mission 2 ・ Exploration Mission 3 ・ Exploration of Africa ・ Exploration of Antarctica ・ Exploration of Energization and Radiation in Geospace ・ Exploration of Io ・ Exploration of Jupiter ・ Exploration of Mars ・ Exploration of Mercury ・ Exploration of Neptune ・ Exploration of North America ・ Exploration of Pluto ・ Exploration of Saturn ・ Exploration of the Americas ・ Exploration of the High Alps ・ Exploration of the Moon ・ Exploration of the Pacific ・ Exploration of the Valley of the Amazon ・ Exploration of the Valley of the Kings ・ Exploration of Uranus ・ Exploration Park ・ Exploration Place ・ Exploration problem Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク Exploration of Mercury ： ウィキペディア英語版 Exploration of Mercury The exploration of Mercury has taken only a minor role in the space interests of the world. It is the least explored inner planet.〔JHU/APL (2006). (MESSENGER: MErcury Surface, Space ENvironment, GEochemistry, and Ranging ) Retrieved on 2007-01-27〕 As of 2015, the Mariner 10 and ''MESSENGER'' missions have been the only missions that have made close observations of Mercury. ''MESSENGER'' made three flybys before entering orbit around Mercury.〔Munsell Kirk-editor (November 06, 2006). (NASA: Solar System Exploration: Missions to Mercury ). Retrieved on 2007-01-27.〕 A third mission to Mercury, BepiColombo, is to include two probes. BepiColombo is a joint mission between the Japan Aerospace Exploration Agency (JAXA) and the European Space Agency. ''MESSENGER'' and BepiColombo are intended to gather complementary data to help scientists understand many of the mysteries discovered by Mariner 10’s flybys. Compared to other planets, Mercury is difficult to explore. The increased speed required to reach it is relatively high, and due to the proximity to the Sun, orbits around it are rather unstable. ''MESSENGER'' is the first probe to orbit Mercury. == Interest in Mercury == Mercury has not been a primary focus of many space programs. Since the planet is so close to the Sun and spins on its own axis very slowly, its surface temperature varies from to .〔Munsell Kirk-editor (November 06, 2006). (NASA: Solar System Exploration: Planet Mercury ). Retrieved on 2007-01-27.〕 As with Venus, the possibility of terraforming Mercury and inhabiting the poles lies far in the future, being significantly less practical than terraforming Mars. The current interest in Mercury is derived from the unexpected observations of Mariner 10. Before Mariner 10, astronomers thought that the planet simply revolved around the Sun in a highly elliptical orbit.〔 The planet had been observed through ground-based telescopes, and Mariner 10 provided data that clarified or contradicted many of their inferences.〔 Another reason why so few missions have targeted Mercury is that it is very difficult to obtain a satellite orbit around the planet on account of its proximity to the Sun, which causes the Sun’s gravitational field to pull on any satellite that would be set into Mercury's orbit. Furthermore, spacecraft naturally accelerate as they approach the greater gravitational pull of the Sun, but must slow down for orbit insertion, so this entails considerable fuel requirements. This is different with superior planets beyond Earth’s orbit where the satellite works against the pull of the Sun. Therefore, reaching an orbit around Mercury requires especially expensive rocketry. Mercury's lack of an atmosphere poses further challenges because it precludes aerobraking or the use of a parachute type device.〔 Thus a landing mission would have even more demanding fuel requirements. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Exploration of Mercury」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.