December 2017

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         Welcome to Observing With Webb, where a high school astronomy teacher tells you what you’re looking at, why it’s so cool, and what you should check out later this month…at night.  Don’t forget to check out my Podbean page, YouTube Channel, and Twitter feed, or get my podcast feed on Stitcher, or iTunes.

The holidays are upon us, and we have some non-magical awesomeness happening in the skies this December, including a great Geminid Meteor Shower, the winter constellations appearing, 2 or 3 morning planets, and a year-end occultation of Aldebaran by the Moon.


PLANETS...well, the ones visible with your naked eye

Planets you can see around Sunset – None

Planets you can see throughout the night – None

Planets you can see in the Morning – Venus (SE – 1st week), Jupiter (SE), Mars (SE)

  • Mercury – Not visible this month.
  • Venus – You MIGHT be able to catch it very low on the horizon the first week as it rises about 30-45 minutes before the Sun does around 7am.
  • Mars – Dim, but 30˚ high in the sky by 7am, rising around 4am. Look SE and find the red object near Jupiter and bright Spica, Virgo’s brightest star.
  • Saturn – Not visible this month.
  • Jupiter – Rises around 5am in early December, getting higher and higher in the sky every morning until it rises at 4am to about 30˚ above the SE horizon on December 30th at sunrise, right below Mars.



Full Moon – 3rd (Visible all night)

Last Quarter Moon – 10th (Visible from midnight into the morning)

13th, 14thGeminid Meteor Shower – A good year for the Geminids, given the moon will be a thin waning crescent rising very late in the morning, giving us a shot at around 100 meteors per hour, depending on your light pollution levels.

Some advice for watching:

  • Find a dark location and lie down in a reclining chair or swimming pool floaty
  • Look at the whole sky, but note Gemini is where the radiant is - where the meteors will appear to be coming from. Gemini will be in the East after sunset, South after midnight, West in the morning.
  • Check the weather to see if the skies will be clear
  • Adapt your eyes to the dark by staying away from light sources or using a red light if you need to look at a star chart or not trip over something. 
  • If you’re feeling extra nerdy, do a scientific meteor count (S&T and IMO)
  • Or find out if your local astronomy club or museum is holding a viewing party.

12th – 15thClose Encounter – Moon, Spica, Mars, Jupiter – Every morning, Jupiter will be super bright, with dimmer red Mars about 10˚ up and to the right, and bright Spica (Virgo’s brightest star) 8˚ up and to the right of Mars and a little brighter.  The Waning Gibbous Moon moves through this collection throughout the 4 days.  On the 12th, the Moon is above Spica, while on the 13th it will make a nice triangle with Spica and Mars.  The next morning, the 14th, the Moon will be about 4˚ above Jupiter, and on the 15th it will move to about 10˚ down and to the left of Jupiter, creating a great 4 object lineup in the morning sky visible after 5am.

New Moon – 18th (darkest skies) 

21stWinter Solstice - The longest night and shortest day of the year for the Northern Hemisphere. More info here:

First Quarter Moon – 26th (Visible until midnight)

30thOccultation – Moon, Aldebaran – Find the Moon with bright Aldebaran right nearby. Witness the motion of the Moon by watching Aldebaran get covered up by it. In my area, the star will disappear at right about 6:20pm behind the dark portion of the Moon, then reappear from the lit portion of the Moon at 7:12pm. Your times will vary, but you can find times here.


CONSTELLATIONS... (see sky map link at the bottom for a Star Map for this month – or ask Mr. Webb)    Look straight up and you'll see...

  • After Sunset (sunset is around 5:00pm) – Pegasus, Andromeda - Extra Challenge!  Using your naked eye (dark-adapted and in a dark area) or binoculars under normal conditions and a star chart, try finding our neighboring Andromeda Galaxy.  It’ll be a faint, but bigger, fuzzy in the constellation Andromeda.
  • Between Sunset and Midnight – Perseus, Andromeda, Cassiopeia
  • Midnight – Auriga, Taurus, Gemini
  • Early Morning – Ursa Major’s legs, Leo Minor


Fall Constellations: Andromeda, Pegasus

If you can find the Summer Triangle and Delphinus in the West, about 40˚ to the East (leftish – pretty much straight above you) will be the Great Square of the fall constellation Pegasus.  Perhaps you’ll even see the two curves of Andromeda off of one side, with the Andromeda Galaxy as a small, faint fuzzy nearby (you’ll need dark skies to see it).  A sky map will help you tremendously in finding these. 

Winter constellations:  Orion is easy to spot as he is rising in the East around 7:30pm.  You can use Orion to find many other winter constellations.

Using Orion:  Find Orion by looking for the three stars in a row that make up Orion’s belt in the East around 7:30pm.  If you draw a line from the left (bottom) star to the right (top) star and keep going right about 20 degrees (about 2 fists at arm’s length) until you reach another very bright star, you will have reached the star Aldebaron in Taurus (the V).  Follow that line a little more (about another fist) and you’ll find the Pleiades.

Draw a line from the right (top) star in Orion’s belt to the left (bottom) star, and keep going left about 20 degrees (2 fists again), you’ll come to the brightest star in the sky – Sirius – part of Canis Major.

Above these three constellations are Gemini and Auriga.  The brightest stars in each of these constellations form a circle in the sky.  Going clockwise - Aldebaron (Taurus) – Rigel (Orion – bottom right foot) – Sirius (Canis Major) – Procyon (Canis Minor) – Castor & Pollux (Gemini) – Capella (Auriga).  It makes for great stargazing in the winter sky.

Use a sky map from to help you out.


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