Mercury at Western Elongation

   On Saturday December 15th Mercury, the innermost planet, will reach its orbital position known as greatest western elongation at 21.3o. At that moment Mercury, the Sun, and the Earth, would be arranged in something close to approximating a right angle as this graphic shows. Even though it sounds confusing at western elongation for either Mercury or Venus the inner planet will be to the right of the Sun as we view them, meaning that at western elongation an inner planet rises in the east before the Sun rises. And at eastern elongation with the inner planet on the left side of the Sun the inner planet follows the Sun across the sky setting after the Sun sets.

   From our perspective the orbits of Mercury and Venus appear to move from one side of the Sun to the other – out to the left (east) from the Sun to eastern elongation, then reverse and move westward (inferior conjunction) between the Earth and the Sun to western elongation. From there the inner planet moves eastward going behind the Sun (superior conjunction) and eventually reappearing on the eastern side of the Sun for an eastern elongation. Repeat over and over – do not stop!


   Mercury is visible in the morning skies just before sunrise local time, as this graphic shows. Venus, to the west from Mercury rises about 2 hours before Mercury, and Jupiter rises shortly after Mercury.

   
   
   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.


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Thin Moon Conjunction with Mercury

   Wednesday morning December 5th the very thin 28-day old waning crescent Moon will be within 4-5o from the innermost planet Mercury. Venus shines very brightly above or west from the Moon. About an hour after the Moon and Mercury have risen the outer planet Jupiter will rise above the eastern horizon.

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.


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Jupiter at Solar Conjunction

   Monday November 26th the outer planet Jupiter will have reached solar conjunction – on the opposite side of the Sun from the Earth. Jupiter will reappear as a morning planet later next month.

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.


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First Quarter Moon Conjunction with Mars

   Over the next two evenings, November 15th – 16th, the first quarter Moon will pass by the planet Mars coming within about 1-2o. The animated graphic is set for 5:30 pm CST on November 15th – 16th.

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.


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November Moon at Apogee

   Our Moon reaches apogee, (greatest distance from Earth), on Wednesday November 14th. At that time the Moon will more or less be at a distance of 31.70 Earth diameters 404,341 km (251,246 miles) from the Earth.

   Does our Moon actually go around the Earth? From our perspective on the Earth the Moon appears to circle around the Earth. However, in reality, the Moon orbits the Sun together with the Earth*

   On the day of the apogee the 7.5-day old waxing crescent Moon, at sunset local time (5:05 pm CST), will be over the southern horizon and joined by several planets. Just over the western horizon are the naked-eye visible planets from west to east: Jupiter, the inner planet Mercury, Saturn, and finally Mars. Neptune is shown however at 8th requires optical assistance or a camera to become visible.

*Click here to read my 2006 Scope on the Sky column “The Real Shape of the Moon’s Orbit”. (PDF)

Read this very informative article about the Earth-Moon system and their orbital motions, written by Joe Hanson. “Do We Orbit the Moon?”

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to go to bobs-spaces.

Moon in Conjunction with Saturn

   Sunday evening November 11th the 3.5-day old waxing crescent Moon will be within 2-3o east (left) of the outer ringed planet Saturn. The two should look good through a wide-field eyepiece at ow magnification, and through binoculars.
   Click here to go to a previous posting showing the daily position of our Moon over a 1.5 week period.

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.


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Our Moon in Motion

Moon in Motion November 7-18

   During the evening hours between Wednesday November 7th – 18th the Moon will orbit eastward passing several planets and bright stars as it goes from a thin waxing crescent shape to just past first quarter and the waxing gibbous shape by the 18th.
    (The animated graphic is set to 1-day intervals.)
    In addition to the Moon moving along in its orbit the Earth is also moving eastward along its orbit around the Sun. As the Earth revolves the sky shifts toward the west gradually moving the stars closer to the western horizon. Even the planets gradually shift toward the western horizon and out of sight.

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.


Also Follow me and other great resources at Feedspot.