Moon Phases
Thu., December 6, 10:31 a.m. EST
Last Quarter Moon
The last or third quarter moon rises around 11:30 p.m. and
sets around 12:15 p.m. It is most easily seen just after sunrise in the
southern sky.
Thu., December 13, 3:42 a.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.
Thu., December 20, 12:19 a.m. EST
First Quarter Moon
The first quarter moon rises around 11:45 a.m. and sets
around 12:30 a.m. It dominates the evening sky
Fri., December 28, 5:21 a.m. EST
Full Moon
The full moon of December is called the oak moon. Other
names are frost moon, winter moon, long night’s moon, and moon before Yule. In
Hindi it is known as margashirsha poornima. Its Sinhala (Buddhist) name is
unduvap. The full moon rises around sunset and sets around sunrise, 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.
Observing Highlights
Sun., December 2, 9 p.m. EST
Jupiter at opposition
Jupiter is directly opposite the sun and, as a result,
shines brightly all night long. Because Jupiter is above the horizon for longer
than its rotation period, it is possible to watch an entire rotation of the planet
in one night. Jupiter joins a circle of seven of the brightest stars in the sky:
Sirius, Procyon, Pollux, Castor, Capella, Aldebaran, and Rigel, with Betelgeuse
at its center.
Tue., December 4, dawn
Mercury at greatest elongation west
The best morning apparition of the year for the elusive
planet Mercury. Venus and Saturn will point to the tiny glimmer of Mercury,
best seen about an hour before sunrise.
Sun., December 9, 3 a.m. EST
Vesta at opposition
Now that Ceres has been promoted from an asteroid to a dwarf
planet, Vesta has become the largest and brightest of the asteroids. Tonight,
at magnitude 6.2, it is slightly too faint to be visible naked eye, but is an
easy object in binoculars.
Tue., December 11, dawn
Mercury, Venus and the moon
The slender waning crescent moon passes just below Venus,
with Mercury nearby.
Fri., December 14, midnight–dawn
Geminid meteor shower
One of the finest meteor showers of the year, without a moon
to block the view.
Tue., December 18, 4 a.m. EST
Ceres at opposition
Once the largest asteroid, Ceres has now been reclassified
as a dwarf planet. At magnitude 6.6, it is an easy target in binoculars. Notice
that Ceres is close to Vesta in the sky. The Dawn spacecraft, after spending
nearly 14 months studying Vesta, left on September 5 to rendezvous with Ceres
in February 2015.
Tue., December 25, 7 p.m. EST
Jupiter and the moon
The moon will pass just south of Jupiter soon after moonrise
in the eastern sky. The two brightest star clusters in the sky, the Hyades and
the Pleiades, are nearby.
Planets
Mercury will be well
placed in the morning sky for observers in the northern hemisphere for the
first half of the month.
Venus is still a
morning “star,” shining brightly before sunrise. It moves from Libra through
Scorpius into Ophiuchus during the month, sinking lower into morning twilight
as it moves towards superior conjunction with the Sun on March 28.
Mars has faded into
the west moving behind the sun. It moves from Sagittarius into Capricornus on
December 25.
Jupiter is in
Taurus, close to Aldebaran and the Hyades. It reaches opposition on December 2
and is visible all night long.
Saturn is now a
morning star. It begins the month in Virgo, but moves into Libra on December 6.
Uranus is visible all
evening in Pisces. It sets around 1 a.m.
Neptune remains in
the depths of Aquarius all month, and sets around 10 p.m.
Geoff Gaherty
Starry Night Software Support
All graphics © 2012 Starry Night Software
