Mercury has begin its evening apparition following its superior conjunction behind the Sun on 2014 AUG 08. This apparition could be nearly impossible to observe after sunset from north of the tropics. That’s due to the sharp angle at sunset between the horizon and the ecliptic near the time of the autumnal equinox.
By the standard of 30 minutes after sunset, Mercury will attain its highest altitude of 2.7° for Chicagoland observers on SEP 11. Greatest Eastern Elongation of 26.4° will be reached on SEP 21. Mercury will be observed in dichotomy (50% illuminated like a Half Moon) on SEP 25. Before then it will appear gibbous and afterward as a crescent. Apparent retrograde motion will commence on OCT 04. While decreasing in brightness, it will fall to inferior conjunction between Earth and Sun on OCT 16.
Mercury will appear near Spica on SEP 20. The Moon will appear to pass near Mercury on AUG 26 and SEP 26.
NOTE: Event dates are for North American Central Time at those moments nearest to 30 minutes after sunset for Chicagoland.