Jan. 1: The moon rises tonight about 7 p.m. Just two days past full, it is still quite bright and remains in the sky until dawn. The bright star to its left and lower is Regulus, in Leo.
Jan. 2: Earth is at perihelion, nearest the sun. The distance is about 147, 096,000 kilometers, or 91,396,000 miles. One effect of perihelion is to raise the highest solar tides of the year, but the lunar tide-producing force is still much greater. The moon tonight is in Leo, but now to the left of Regulus and closer to the star.
Jan. 4: The moon rises tonight about 11 p.m., midway between Regulus to its right, and Spica, brightest star in Virgo, to its left. The moon is just one day before last quarter, located just above the point in Virgo known as the autumnal equinox, where the sun is located on Sept. 23. The object to Spica's left is the planet Saturn.
Jan. 6: The latest sunrise of the year occurs in the mid-latitudes of the Northern Hemisphere. Sunset now occurs significantly later than it did in mid and late December. Last quarter moon, rising after midnight with Spica, is in Virgo. Mercury begins moving westerly (its retrograde motion) among the stars as it approaches inferior conjunction later in January.
Jan. 7: The two bright objects to the right of the crescent moon in the dawn sky this morning are Saturn, the closer, and Spica. Jupiter is lower, well to the left, and brighter than Saturn.
Jan. 9-10: Watch the crescent moon move from west to east past Jupiter in the morning sky of these two dates. On the 9th, the moon is above and to the right of Jupiter, on the 10th it is below and to the left. Saturn and Spica are close to one another, higher and to the right on both mornings.
Jan 13-14: Apogee (farthest from earth) just about coincides with the new moon during this night, both taking place very close to midnight.
Jan. 15: Venus is in conjunction with the moon, but they set too soon after sundown to be visible. Mercury, in inferior conjunction (passing between earth and sun), moves to the sun's right and enters the morning sky.
Jan. 16: Mars is in conjunction with the moon late today, above and to its right in the evening twilight sky, but too dim and too low to be seen easily.
Jan. 17: The early crescent moon should be visible tonight, weather permiting , well up in the southwest after sundown, among the dim stars of Aquarius.
Jan. 19: When the moon appears during early evening, it is in Pisces, a little below and to the east of the vernal equinox, the point in the sky known as the First Point of Aries. But the moon isn't in Aries until the night of Jan. 22-23.
Jan 21-22: First quarter moon occurs tonight, shortly after midnight in eastern standard time. Thus first quarter falls early in the 22nd along the East Coast of the United States, but late on the 21st in time zones to the west.
Jan. 24: The waxing gibbous moon is well up in the southeast at dusk, above the bright star Aldebaran in Taurus. The moon passes above Aldebaran (conjunction) in the early evening.
Jan. 27: Mercury, now a morning star, but poorly placed for viewing, resumes its direct (easterly) motion through the stars.
Jan. 28: The full moon is in Cancer tonight, about midway between the twin stars Pollux and Castor, in Gemini, to its right, and Regulus, in Leo, to its left. Perigee moon (nearest earth) occurs only 11 hours before full moon, and the effect of perigee will enhance the normally strong tides that accompany syzygy (a challenging word meaning that sun, earth, and moon are in line). Flooding could occur along low-lying coastal areas tonight and tomorrow morning especially if strong winds blowing onshore add to the problem.
Jan. 29: The moon is close to Regulus for the second time this month, passing above the bright star in Leo about midnight (EST). Note that the moon is now just one day past full, while last time it was near Regulus (on Jan. 2), it was several days later in phase, more than three days past full.
Jan. 30: Still in Leo, the moon is now well to the east (left) of Regulus.
Jan. 31: The moon ends the month entering Virgo, passing above the autumnal equinox, south of the star Denebola in Leo, as it did on the 4th. But while it was just about at last quarter when it passed here previously, it is a fat, waning gibbous moon tonight, rising about 9 p.m. and lighting sky and earth until dawn.
All month: Winter evening stars this year put on their usual brilliant display. It's best in the Caribbean and Gulf of Mexico where the stars include Canopus (second brightest star we see, after Sirius) and the Southern Cross. But this winter, perversely, no planets are obvious among them, even though three of the brighter ones - Mercury, Venus, and Mars - are evening stars for at least part of the month.
The planets farther out than Mars are in the morning sky, and the bright ones , Jupiter and Saturn, are coming into good position as morning stars. Both are still near the bright star Spica, in Virgo, Saturn close by to its left and matching it in brilliance, Jupiter well to the left and much brighter. The three objects, star and two planets, should be readily visible on any clear morning, in the southeast at dawn. The waning crescent moon moves past them during the first week of January.