On New Year’s evening, a very slender crescent moon can be seen right after sunset, well below Venus. By January 2, the Moon will move just below Venus, and by the 3rd, it will be above Venus. If the afternoon is clear, this would be an ideal time to catch Venus with your naked eyes in broad daylight, for it is near its brightest, and will be just below and to the right of the crescent moon before sunset. By the 4th, the moon now sits above the planet Saturn in the Southwest.
The Earth is closest to the Sun at perihelion on January 4, only 91.4 million miles from our home star. Doesn’t feel like it? Our orbit is so close to a perfect circle that the small change between perihelion and aphelion in July is overshadowed by our 23.5 degree axial tilt. We just passed winter solstice in December, when our northern hemisphere is tilted away from the Sun, hence longer nights and the sun 47 degrees lower in the sky than in summer, and for our area, the days are four hours shorter now.
The first quarter moon on January 6th. The waxing gibbous moon passes just north of Jupiter in the NE. The big action is with the occultation of Mars by the Full Moon on the evening of January 13th. Stellarium indicates the Red Planet will disappear near the south pole of the Moon about 9:03 p.m., and as you see below, reappear on the NW limb about an hour later, at 10 p.m.. Note the moon moves its own ½ degree diameter eastward every hour in its orbit of the earth, as this event shows nicely. The last quarter moon occurs on January 21st. The new moon is on January 29th.
Mercury is lost in the Sun’s glare all month. By contrast, Venus dominates the SW evening sky, reaching greatest eastern elongation, 47 degrees up from the setting sun, on January 11th. It will then appear exactly half lit in small telescopes, but the bright disk of sulfuric acid clouds will reveal no detail except the phase. It moves much faster than distant Saturn, and will overtake the ringed planet on January 18th; note how thin the rings, almost edge on now, appear in your scopes. Venus will become a larger crescent in your scope after this, as it overtakes the Earth in the next three months.
By contrast, Mars will be at opposition on January 15th, two days after the moon occulted it. It will be largest in the sky as seen from Earth then, some 15" across, and brightest, magnitude -1.4. Contrast its bright red color to equally bright blue Sirius, the brightest star in the sky, rising in the Southeast at the same time. At the end of this month, the planet parade goes from Venus (overtaking Saturn on the 18th), then Jupiter almost overhead in Taurus, and Mars in Cancer on the Northeast horizon at sunset. Jupiter is well placed for observing high up in the East just below the V shaped Hyades cluster in Taurus. Note the four Galilean moons in a row around Jupiter’s equator with small scopes, and how they change places night by night.
The constellation Cassiopeia makes a striking W in the Northwest. Her daughter, Andromeda, starts with the NE corner star of Pegasus’’ Square, and goes Northeast with two more bright stars in a row. From the middle star, beta Andromeda, go about a quarter the way to the top of the W of Cassiopeia, and see 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.
Overhead is 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% of the smaller but hotter and thus brighter companion as seen from Earth.
Look at Perseus’ feet for the famed Pleiades cluster; 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.
Yellow Capella, a giant star the same temperature and color as our much smaller Sun, dominates the overhead sky. 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 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.
South of Gemini, Orion is the most familiar winter constellation, dominating the eastern sky at dusk. The reddish supergiant Betelguese marks his eastern shoulder, while blue-white supergiant Rigel stands opposite on his west knee. 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. It is part of a huge spiral arm gas cloud, with active star birth all over the place. You should be able to glimpse this stellar birthplace as a faint blur with just your naked eyes, and the larger your binoculars or telescope, the better the view becomes.
To warm your winter nights, here is the "Flame Nebula", just east of the lower star in Orion’s rising belt. Just south of it is the famed dark nebula, "the Horsehead", a dark cloud in front of the glowing hydrogen background here. While M-42 is an emission nebulae, shining reddish from the ionization of its hydrogen gas by hot young stars forming inside it, at Orion’s right foot is brilliant Rigel, one of the most luminous blue super giants ion the Galaxy, about 50,000X more luminous than our Sun.
Last but certainly not least, in the east rise the hunter’s two faithful companions, Canis major and minor. Procyon is the bright star in the little dog, and rises minutes before Sirius, the brightest star in the sky. Sirius dominates the SE sky by 7 PM, and as it rises, the turbulent winter air causes it to sparkle with shafts of spectral fire. Beautiful as the twinkling appears to the naked eye, for astronomers this means the image is blurry; only in space can we truly see "clearly now". At 8 light years distance, Sirius is the closest star we can easily see with the naked eye.
