Mercury at greatest elongation east
2013 Jun 12
Mercury will reach its furthest point east of the Sun in the evening sky, so that it will set over an hour behind the Sun, appearing prominent at mag -1.9 on the western horizon for a brief time shortly after sunset. At the moment of greatest elongation, Mercury will lie in the constellation Gemini, at a distance of 24°16′ from the Sun. Its declination will be +23°36’11” , and so it will be seen to best advantage in the northern hemisphere; in fact, it will be unobservable from latitudes south of 46°S.