Mercury: greatest elongation, north of Sun

Event Date: February 16th

Time: 6:33 PM

Brief

   Mercury has slowly faded over the last couple weeks, yet not too noticeably.  It has pulled to 18.1º from the Sun for greatest eastern elongation (g.e.e.), and reaching perihelion as well today at 28.6 million miles from the Sun; the time for that is shown above.  Also barely seen about 5.2º from Mercury closer to the horizon is Mars (optical aid required), although much dimmer being several times further away.  While Mars is deeper in atmospheric pollution once first found in binoculars or--even better--a telescope, Mercury is far enough out of it for a good showing.  The image shows both planets, Mercury's orbit, as well as the celestial guidelines.

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

Detailed

   Since Earth is only about 5 weeks removed from perihelion ourselves, we are less than 87 million miles from Mercury, contributing to it still seeming bright, at magnitude -0.4. The ecliptic's excellent angle with the horizon shows how much more north Mercury is of the Sun: over 7 1/2º.  The gap continues to increase for a few more days, although Mercury will start to dim a little faster as it continues to wane in phase and move back towards the Sun in [angular] separation.  Eventually, it reaches inferior conjunction yet before that, begins retrograde and the separation between the two shrinks rapidly.  As a result of this, the declination gap shrinks quickly as well.

   As for Mars, if you can still barely see it with optical aid through the atmospheric pollution as a dim ''star", this may be the last week that you can do so.  As the Sun moves closer to the celestial equator quickly over the next several weeks while catching up with Mars in prograde motion, the now-not-so-red-planet will become lost in its glare.  Good luck trying to see it, and using the image, notice that it is almost directly below Mercury.  At only 3º at the time above, be at a location where there is no obstruction; a mountain summit may your best bet!  Keep in mind however, as a reminder, that the software doesn't take atmospheric pollution in account.  Therefore, the last few weeks of showing it here, have it brighter than it is, seen with the eye.