View Full Version : Mercury as March-April Evening Star

2011-Mar-05, 04:39 PM
The elusive little planet Mercury has begun its apparition as an evening star following its superior conjunction behind the Sun on 2011 FEB 25. This will be a fine apparition for observers in the northern hemisphere: the best for the next two years. However, it will be an almost impossible one for folks south of the tropics.

I’ve created two graphics illustrating Mercury’s evening apparition as viewed from Chicagoland and Sydney. However, they should well serve most observers in the respective hemispheres. I’ve also made charts comparing Mercury’s maximum early evening altitudes over many apparitions for both hemispheres. They can all be seen by clicking http://www.curtrenz.com/mercury

All dates given here are based on North American Central Time. Mercury will achieve dichotomy (50% illuminated like a Half Moon) on MAR 20. Before then it will appear gibbous and afterward a crescent. Mercury will reach its greatest eastern elongation of 18.6° from the Sun on MAR 22. On that same date it will attain its greatest altitude at 30 minutes after sunset for Chicagoland at 11.9°. While decreasing in brightness, it will then fall to inferior conjunction between Earth and Sun on APR 09.

A slender young crescent Moon will be hovering above low Mercury after sunset on MAR 05 and APR 04. Mercury will pass 2.0° north of Jupiter on MAR 15. Mercury will make no other close angular approaches to planets or bright stars during this apparition.

Photos and descriptions of Mercury during the current evening apparition would be welcome additions to this thread.