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Moon near Jupiter, Gemini stars and Orion on December 17

Moon near the planet Jupiter and the stars Castor and Pollux on December 17. Read more

Tonight for December 17, 2013

Although the moon will look plenty full tonight, it’ll actually be a waning gibbous moon for most of the world as darkness falls tonight (December 17). The last full moon of 2013 occurred on December 17 at 3:28 a.m. CST or 9:28 UT on December 17. This is the smallest full moon of 2013.

Look for tonight’s full-looking moon to be in fairly close vicinity of the constellation Orion and the dazzling planet Jupiter. At mid-evening at mid-northern latitudes, Jupiter is seen to the north (left) of tonight’s moon while the constellation Orion is seen to the south (right) of the moon.

On the moonless evening of December 3, 2013, Chris Georgia took this gorgeous photo of the constellation Orion (above his head and left of the light pole), the planet Jupiter (brightest star-like object at left), and the Gemini stars to Upper left of Jupiter: Castor (at top) and Pollux (at bottom). Thank you so much, Chris! View larger

On the moonless evening of December 3, 2013, Chris Georgia took this gorgeous photo of the constellation Orion (above his head and left of the light pole), the planet Jupiter (brightest star-like object at left), and the Gemini stars to Upper left of Jupiter: Castor (at top) and Pollux (at bottom). Thank you so much, Chris! View larger

A somewhat smaller waning gibbous moon will pair up more closely with Jupiter tomorrow, on December 18.

Orion the Mighty Hunter, it seems, is everyone’s favorite constellation. It’s little wonder. This configuration has a distinctive pattern – looks vaguely like its namesake, a hunter holding a shield before him with an upraised club – and is filled with a greater number of bright shining stars than any other constellation.

As seen from mid northern latitudes (like in the United States and Europe), Orion assumes a recumbent position at early evening, with his famous belt of three moderately bright stars jutting upward. You’ll always find Orion’s two brightest and most colorful stars – Betelgeuse and Rigel – on opposite sides of Orion’s Belt. Ruddy Betelgeuse is to the north (or left) of the belt, while sparkling blue-white Rigel lies to the south (or right).

The constellation Orion and the Winter Triangle are even visible from a light-polluted city. Thank you Indrajit Dutta for sharing your photo! View larger

The constellation Orion and the Winter Triangle are even visible from a light-polluted city. Thank you Indrajit Dutta for sharing your photo! View larger

Once you come to know the constellation Orion, you’ll find it is your faithful guide to many other stars and star patterns.

Once you’re familiar with Orion, you can star-hop to numerous stars and constellations. For instance, by drawing a line from Mintaka (the top star of Orion’s Belt) through Betelgeuse, you can locate the two brightest stars of Gemini the Twins (and in 2013 the nearby dazzling planet Jupiter): Castor and Pollux. Orion’s Belt points northwest to the constellation Taurus’ brightest star Aldebaran . In the opposite direction, Orion’s Belt points southeast to the constellation Canis Major’s brightest star Sirius, the brightest of the nighttime sky.

But don’t stop there! An imaginary line from the star Bellatrix and to the south Betelgeuse escorts you to Procyon, the brightest star in the constellation Canis Minor. Or look between Orion and Polaris, the North Star, to locate Capella, the brightest star of the constellation Auriga the Charioteer.

Winter Circle: Brightest winter stars

Star trails of Orion, from EarthSky Facebook friend Jean-Baptiste Feldmann. See the three Belt stars? Thank you, Jean-Baptiste!

Bottom line: Tonight’s moon – December 17, 2013 – is not far from the constellation Orion the Hunter. After rising tonight, Orion and the moon will travel upward and westward throughout the night. They’ll be highest up in the middle of the night and will set in the west before the onset of dawn. Despite the moonlit glare tonight, you should be able to make out the constellation Orion and the bright wintertime stars!