Today Mercury will be at maximum eastern elongation, as high in the evening sky as it will appear for this current apparition. After today the planet will slide back into the sunset, passing through inferior conjunction on August 26th to reappear in the morning sky in mid-September.
Mercury typically completes three morning and three evening apparitions in each year. While the innermost planet never gets very far from the Sun, maximum elongation represents the best time to observe Mercury as high in the sky as possible.
There are no transits of Mercury in 2017, the next will be Nov 11, 2019.
|Mercury Events for 2017|
|Maximum Elongation||Jan 19||24.1°W||+0.0|
|Superior Conjunction||Mar 6|
|Maximum Elongation||Apr 1||19.0°E||+0.2|
|Inferior Conjunction||Apr 19|
|Maximum Elongation||May 17||25.8°W||+0.7|
|Superior Conjunction||Jun 21|
|Maximum Elongation||Jul 30||27.2°E||+0.6|
|Inferior Conjunction||Aug 26|
|Maximum Elongation||Sep 12||17.9°W||-0.1|
|Superior Conjunction||Oct 8|
|Maximum Elongation||Nov 24||22.0°E||-0.1|
|Inferior Conjunction||Dec 12|
|Source: NASA Sky Calendar and the Mercury Chaser’s Calculator|