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Mars comes close to earth near Christmas
For December, the Moon will be last quarter on December 1st. The first week of December will thus find the Moon waning and rising later each evening. The waning crescent moon is passing about 6 degrees south of Venus on December 3rd. The new moon occurs on December 9th. The next two weeks find the moon waxing in the evening sky. First quarter moon sits high in the sky and half-lit at sunset on December 17th. The winter solstice occurs just after midnight on December 22, 2007; this is the shortest day of the year, so the full moon that follows is the Yule or Long Night Moon, and occurs on December 24th. The moon will be just a degree north of bright red Mars then; Mars is at opposition the same day. The last week of December finds the moon waning in the morning sky, passing 2.5 degrees south of Saturn on December 28; both rise about 10 PM due east.
While the naked eye, dark adapted by several minutes away from any bright lights, is a wonderful instrument to stare up into deep space, far beyond our own Milky Way, binoculars are better for spotting specific deep sky objects. For a detailed map of northern hemisphere skies, about Halloween visit the www.skymaps.com website and download the map for December 2007; it will have a more extensive calendar, and list of best objects for the naked eyes, binoculars, and scopes on the back of the map.
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Also available as the next month begins is wonderful video exploring the December 2007 sky, featuring many different objects, available from the Hubble Space Telescope website at: http://hubblesite.org/- explore_astronomy/- tonightssky/.
Venus dominates the morning sky; telescopically she appears as a small, gibbous disk. She is now on the far side of her orbit, and will pass behind the Sun in early 2008. It was Galileo in 1611 who noted that Venus goes through this entire phase cycle, and correctly deduced this proved she orbited the Sun, not us. Covered with sulfuric acid clouds, her bright disk reveals no visible details in the scopes.
This is the month of observing red Mars, coming to opposition and closest to earth about Christmas. The Escambia Amateur Astronomers will host two "Mars Mania" gazes for the public, at the PJC planetarium on the Saturday evenings before and after Christmas (Dec. 22 and 29), clear skies permitting, starting about 6 PM. Bring along your digital camera to get great shots of the red planet off the video monitors. EAAA Observatory Chairman Paul Moffat's shot of Mars back in July 2003 shows the red planet with its south polar cap still very bright at bottom. While Mars will not get as close and bright this December, it will be well placed high in the sky for viewing, and much disk detail should be visible this month with amateur telescopes.
The square of Pegasus dominates the western sky. The constellation Cassiopeia makes a striking W in the NW. She contains many nice star clusters for binocular users in her outer arm of our Milky Way, extending to the NE now. Her daughter, Andromeda, starts with the NE corner star of Pegasus'' Square, and goes NE with two more bright stars in a row. It is from the middle star, beta Andromeda, that we proceed about a quarter the way to the top star in the W of Cassiopeia, and look for a faint blur with the naked eye. M-31, the Andromeda Galaxy, is the most distant object visible with the naked eye, lying about 2.5 million light years distant. To the northeast, Andromeda's hero, Perseus, rises. Between him and Cassiopeia is the fine Double Cluster, faintly visible with the naked eye and two fine binocular objects in the same field. Perseus contains the famed eclipsing binary star Algol, where the Arabs imagined the eye of the gorgon Medusa would lie. It fades to a third its normal brightness for six out of every 70 hours, as a larger but cooler orange giant covers about 80 percent of the smaller but hotter and thus brighter companion as seen from Earth.
Check it out on a clear December evening, and see it the gorgon is winking at you. If so, then instead of being as bright as Polaris, Algol fade to be only as bright as kappa Persei, the star just to its south.
On October 24, a faint, obscure comet, 17P/Holmes, suddenly exploded just east of Mirfak, the brightest star in Perseus, becoming a million times brighter than normal, and an easy naked eye object for about three weeks. The expanding coma grew larger than the size of the Full Moon in the sky, and in reality, since the comet is 1.5 times farther from us than the Sun is, the coma was bigger than the bright photosphere of our Sun! But it is fading fast, and will not be a naked eye object in December, unless it has a sudden revival (which has happened before to this strange ice berg in space).
Look at Perseus' feet for the famed Pleiades cluster to rise, a sure sign of bright winter stars to come; they lie about 400 light years distant, and over 250 stars are members of this fine group. East of the seven sisters is the V of stars marking the face of Taurus the Bull, with bright orange Aldebaran as his eye. The V of stars is the Hyades cluster, older than the blue Pleaides, but about half their distance.
Mars now moves in retrograde from Gemini into the horns of Taurus as December begins, and is at greatest brilliance at opposition around Christmas.
Yellow Capella, a giant star the same temperature and color as our much smaller Sun, dominates the NE sky until even brighter Mars rises about an hour later. It is part of the pentagon on stars making up Auriga, the Charioteer (think Ben Hur). Several nice binocular Messier open clusters are found in the winter milky way here. East of Auriga, the twins, Castor (closer to Capella, rising first about 7:30 PM as December begins) and Pollux highlight the Gemini. UWF alumni can associate the pair with Jason and the Golden Fleece legend, for they were the first two Argonauts to sign up on his crew of adventurers.
South of Gemini, Orion is the most familiar winter constellation, dominating the eastern sky by 8 PM. The reddish supergiant Betelguese marks his eastern shoulder, while blue-white supergiant Rigel stands opposite on his west knee. The three stars in a row that mark his belt have a Christmas association in Latin America. As "Los Tres Reyes," they stand for the three kings, bringing gifts to the Christ Child.
Just south of the belt, hanging like a sword downward, is M-42, the Great Nebula of Orion, an outstanding binocular and telescopic stellar nursery. he bright diamond of four stars that light it up are the Trapezium Cluster, one of the finest sights in a telescope. Next month, we will meet Orion's faithful companions, Canis major and minor, and the brightest star in the sky.
For more information on the Escambia Amateur Astronomers and our local star gazes for the public, visit our website at www.eaaa.net or call sponsor Dr. Wayne Wooten at PJC at (850) 484-1152, or e-mail him at wwooten@pjc.edu.
The Escambia Amateur Astronomers will host two "Mars Mania" gazes for the public, at the PJC planetarium on the Saturday evenings before and after Christmas (Dec. 22 and 29), clear skies permitting, starting about 6 p.m. Bring along your digital camera to get great shots of the red planet off the video monitors.
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