Mercury--before good morning apparition

Event Date: November 20th

Time: 6:30 AM

Brief

   We have not had a good apparition of Mercury in the morning sky since very early in the calendar year.  It is during September and early October that we have some of the best geometry of the sky looking east in the morning.  However, for the last couple of years, Mercury has spent time setting after the Sun for periods close to two months, during that [time] frame.  Now, we have it back in the morning while the geometry is slowly failing, yet still decent enough to give us a very good view of Mercury.  Here it is, quickly emerging from the Sun while still in retrograde.  In about a week, it will start to become visible with optical aid and then about a week later, with the eye.  The orbit shows below in the image, and look at the angle with not only the horizon, yet the ecliptic as well!

click on image to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

Detailed

As shown, and hinted at the end of the brief, Mercury's ecliptic latitude will improve enough over the next several days, that it will not be too affected by the geometry of this part of the morning sky getting a little worse each week.  Mercury will become a little further north of the Sun each day that it moves in retrograde and therefore, will become visible out of the glare before long.  That, and it is just past perihelion, which happened about a week ago.  Therefore, as it emerges from the Sun, it will move far enough away from it that it stays close enough to us.  Since we are moving towards perihelion ourselves on Earth, we are moving a bit towards the sun while Mercury moves slowly away from it.  At the same time, Mercury's perihelion helps it reflect more Sunlight and brighten quickly between now and greatest western elongation.