December’s visible (and some invisible) Planets


 MERCURY turns Evening Star in December, until his encounter with the Sun on December 20 (Inferior Conjunction).

Our small brother will become first Stationary and then Retrograde between December 10 and 30.

Mercury transited very close to Mars at the end of November (visible conjunction on November 21, 22), and he will meet Mars again, in retro motion this time, on December 14. By then both planets will be low on the western horizon to be visible, too close to the glare of the setting Sun.

By December 13, Mercury will have disappeared as a Evening Star, only to re-appear early on Christmas day as a Morning Star.

It will rise at first half hour before sunrise,  ending up rising one and a quarter hours before the Sun by the end of December. It will remain visible until morning twilight to the end of the month and beyond.

Since November 4 VENUS has been rising before the Sun, a brilliant Morning Star in the company of Saturn. In December Venus will slowly distance herself from Saturn, powering ahead in direct motion. The day of greatest illumination will be December 4.

Throughout the month Venus will rise at first about two hours before the Sun and, by the end of December, around three hours before the Sun. She will disappear only in the morning twilight.

It could be worth while to get up early on December 2, and 4 to watch a beautiful display of Venus with the old Moon, Saturn and the Star Spica, aligned together in the East, around 4, 4.30 am (keep an eye on the Stargazing link here and on Living Moon opening page for sky-scapes of this and other events).

MARS is disappearing from the western horizon in December, more and more immersed in the light of the Sun, inching ever closer to the horizon. Mars will make his next appearance in the East, as a Morning Star before sunrise, in mid-April 2011, against the Pisces Constellation and in the Tropical Sign of Aries.

JUPITER can be readily spotted in in the night time in December, exceptionally bright with a pair of binoculars or a telescope. Our giant neighbor becomes visible around  7 pm in the evening and disappear around midnight, the Sun reaching a distance of 90 degrees from Jupiter on December 17.

With a pair of good binoculars we could even be able to spot far away URANUS, with Jupiter pulling close to the eccentric planet during December. Uranus appears as a bluish/green star-like object,the brightest in the vicinity of Jupiter.

Jupiter and Uranus became conjunct for the first time in nearly 14 years on June 9. Jupiter and Uranus meet cyclically (synodical cycle) every 13.7 years. This time they are playing a prolonged duet, though, having  met twice in 2010 (June 9 and September 22) and a third time on January 2, 2011. This is a rarer opportunity for the energies of these planets to blend for a sustained period, so exerting a greater overall influence over the affairs of the whole year. The last time Jupiter and Uranus met three times was in 1983, 27 years ago.

Animation of the triple conjunction of Jupiter-Uranus in 2010/11, from Martin J.Powell astronomical site, can be found HERE.

SATURN will be visible after midnight throughout the month, and remain well visible, high in the sky, until sunrise.


The GEMINIDS METEORS SHOWER will have its annual occurrence between December 6 and 19, with the period of high visibility and frequency around December 13 and 14. This is considered by many the best Meteors’ Shower of the year. It is known to produce 60 to 80 multi-coloured meteors per hour, at its peak. From locations away from artificial light there could be up to 120 meteors per hours!

The radiant point (from where the meteors seem to originate) will be in the Constellation Gemini, becoming visible before midnight toward the North-East. The Moon setting in the West at the same time will allow for a better show.

The known source of this shower is a strange object called Phaethon 3200, most probably a comet which became extinct a long time ago. The asteroid, that measures 5.10 km diameter, was discovered in 1983. Phaethon in Greek Mythology was the son of Helios, the Sun god, himself a demi-god who perished after attempting to get too close to the Sun in the chariot he had stolen from his father. The asteroid was named after him because it crosses the orbits of Earth, Venus and Mercury, and gets closer to the Sun than any other numbered asteroid.

The URSIDS METEORS SHOWER will occurs instead between December 17 and 24, with the peak on December 22. This is a less spectacular shower, with about 9, 10 meteors expected per hour, at peak. The shooting stars will appear to emanate from the constellation Ursa Minor, home to Polaris in the north. Because of their location the Ursids are not really visible from our Southern Hemisphere.


This event will be visible mainly from North America and the west side of South America.

In most countries in Europe and Africa the Moon will be setting during the Eclipse proper. Only from Southern Scandinavia the Eclipse will be observable in its entirety.

In East Asia instead the Moon will be rising during the event.

People in South and East Africa, as well as in the Middle East and South Asia will not be able to witness the event. With the exception of Western Australia, where the Eclipse will not be visible at all, the rest of the continent will witness the event partially around Moon rise, with the Moon very close to the Eastern horizon. The total stages instead will be partially visible from New Zealand but not from Australia. In the northern parts of New Zealand the Eclipse will be visible in its totality. Further South only parts of the total stages will be visible.

Not the best Eclipse for the Southern hemisphere.

For more information on this Eclipse and others please navigate to the Nasa Eclipse Page here.

All the Sky Snapshots have been generated using Stellarium, a wonderful Planetarium freeware software.

Information for the Sky Events has been gathered from these web sites:

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