Sky Events December 2012

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