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A transit of Mercury across the Sun as seen from Mars takes place when the planet Mercury passes directly between the Sun and Mars, obscuring a small part of the Sun's disc for an observer on Mars. During a transit, Mercury can be seen from Mars as a small black disc moving across the face of the Sun. Transits of Mercury from Mars are much more common than transits of Mercury from Earth: there are several per decade. No one has ever seen a transit of Mercury from Mars, but they could be observed by future Mars colonists. The Mars Rovers ''Spirit'' and ''Opportunity'' could have observed the transit on January 12, 2005 (from 14:45 UTC to 23:05 UTC); however the only camera available for this had insufficient resolution. They were able to observe transits of Deimos across the Sun, but at 2' angular diameter, Deimos is about 20 times larger than Mercury's 6.1" angular diameter. Ephemeris data generated by (JPL Horizons ) indicates that ''Opportunity'' would be able to observe the transit from the start until local sunset at about 19:23 UTC, while ''Spirit'' would be able to observe it from local sunrise at about 19:38 UTC until the end of the transit. The Curiosity rover observed the Mercury transit of June 3, 2014, marking the first time any planetary transit has been observed from a celestial body besides Earth.〔 The Mercury-Mars synodic period is 100.888 days. It can be calculated using the formula 1/(1/P-1/Q), where P is the orbital period of Mercury (87.969 days) and Q is the orbital period of Mars (686.98 days). The inclination of Mercury's orbit with respect to that of Mars is 5.16°, which is less than its value of 7.00° with respect to Earth's ecliptic. ==Transit visibility table== 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「Transit of Mercury from Mars」の詳細全文を読む スポンサード リンク
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