Moon Phases
Saturday, December 6, 7:27 a.m. EST
Full Moon
The Full Moon of December is known as the “Oak Moon,” “Cold Moon,” or “Long Nights Moon.” It rises around sunset and sets around sunrise; this is the only night in the month when the Moon is in the sky all night long. The rest of the month, the Moon spends at least some time in the daytime sky.
Sunday, December 14, 7:51 a.m. EST
Last Quarter Moon
The Last Quarter Moon rises around 11:45 p.m. and sets around 12:15 p.m. It is most easily seen just after sunrise in the southern sky.
Sunday, December 21, 8:36 p.m. EST
New Moon
The Moon is not visible on the date of New Moon because it is too close to the Sun, but can be seen low in the East as a narrow crescent a morning or two before, just before sunrise. It is visible low in the West an evening or two after New Moon.
Sunday, December 28, 1:31 p.m. EST
First Quarter Moon
The First Quarter Moon rises around noon and sets around 1 a.m. It dominates the evening sky.
Observing Highlights
Monday, December 1, 7 p.m. EST
Uranus and the Moon
The waxing gibbous Moon will pass just north of the planet Uranus. Observers in northwestern Canada and eastern Alaska will see the Moon occult Uranus, as in this view from Yellowknife, NWT, Canada.
Friday, December 5, midnight EST
Aldebaran and the Moon
The nearly full Moon passes just north of the red giant star Aldebaran and the Hyades star cluster. The bright Pleiades star cluster is above and towards the West.
Monday, December 8, 11:20–11:25 p.m. EST
Double shadow transit on Jupiter
For a brief 5-minute period, the shadows of both Io and Europa will fall simultaneously on opposite limbs of Jupiter, the first of a series of double transit events culminating in a triple shadow and satellite transit on January 24, 2015.
Sunday, December 14, 7 a.m. EST
Geminid meteor shower peaks
A last quarter Moon will interfere with viewing this most reliable meteor shower. The best meteors will be visible about 90 degrees away from the radiant in Gemini.
Tuesday, December 16, 1:12–02:02 a.m. EST
Double shadow transit on Jupiter
For 50 minutes the shadows of both Io and Europa will fall simultaneously on Jupiter. Note that this event occurs after midnight on Monday, December 15.
Friday, December 19, 1 hour before sunrise
Saturn and the Moon
Saturn makes a reappearance as a “morning star” close to the slender waning crescent Moon, just before sunrise Friday morning.
Sunday, December 21, 6:03 p.m. EST
Winter solstice
The Sun reaches its southernmost position in the sky, and begins moving northward again. New Moon is less than 3 hours away, so the Moon is close by, and the Sun is flanked by four planets (Mars, Venus, Mercury, and Saturn) and two dwarf planets (Pluto and Ceres). As happens every year at the solstice, the Sun is only a few degrees away from “alignment” with the black hole at the center of our Galaxy. This is the summer solstice in the Southern Hemisphere.
Sunday, December 28, midnight EST
Uranus and the Moon
The waxing gibbous Moon again passes just north of the planet Uranus. Observers in northeastern Asia, Alaska, and northern Canada will see the Moon occult Uranus, as in this view from Yellowknife, NWT, Canada.
Planets
Mercury is too close to the Sun to observe all month.
Venus reappears as an “evening star” in the southwestern sky just after sunset at the beginning of the month.
Mars moves from Sagittarius into Capricornus on the 4th low in
the southwestern sky, moving behind the Sun. Mars is at its closest to
the Sun (perihelion) on the 12th, and spring is well advanced in its
southern hemisphere.
Jupiter now rises in mid-evening in the constellation Leo, and
shines brightly in the southern sky the rest of the night. A two-month
series of double shadow transits begins on December 8.
Saturn reappears in as a “morning star” in Libra in the southeastern dawn sky.
Uranus is well placed in Pisces in the evening sky, setting after midnight. Two close approaches by the Moon on the 1st and 28th will make it easy to spot.
Neptune is in the early evening sky in Aquarius, setting in late evening.
Geoff Gaherty
Starry Night Software Support
All graphics © 2014 Starry Night Software
