The Moon grows through its waxing crescent
phase this week, hitting
first quarter on Thursday, December 8, after which it begins to
expand through the waxing gibbous ("waxing" from old English, "to
grow bigger," related to the German "wachsen" of the same meaning).
The night of Saturday the 3rd finds the Moon low above the
southwestern horizon, while the following night, Sunday the 4th, it
makes a near classic pairing with brilliant
Venus, the Moon to the left of the second planet from the Sun, an event well worth the look in
twilight, the nighttime side of the lunar disk illuminated with Earthlight. On Monday the 5th and
Wednesday the 7th, the Moon respectively passes south of
Neptune (still in Capricornus)
and Uranus (in Aquarius).
In the deep southwest, Venus, still
setting around 7:30 PM, well over an hour after the end of
twilight, is still slightly increasing in brightness. Maximum
brilliance will be reached on Friday the ninth. Venus, third
brightest object in the sky after the Sun and Moon, is visible in
full daylight -- if you know just where to look or are lucky to
happen on to it. In the other direction, it is not difficult to
find number five in brightness, Mars, which is well
up in the east as the sky darkens.
The sky is exhibiting some remarkable symmetry. In southern Aries,
Mars crosses the meridian to the south about 9:30 PM, just half an
hour later than Saturn rises
in Cancer. Then, if you can stay
awake or get up early, follow Saturn until it crosses the
meridian at 4 AM, just about the time Jupiter (number four in
brightness) rises and Mars sets. Finally, as twilight begins, Mercury rises, the little planet barely visible in the
light of growing dawn.
Among the most enchanting of constellations, Cassiopeia, with her "W" and "Chair," rides high above
the North Celestial Pole in mid-
evening. In a dark sky, it is seen set into a lovely part of the
Milky Way that comes out of Perseus and then departs to the west
into southern Cepheus. Between
Cassiopeia and Perseus (and technically in the latter), you might
spot the fuzzy ball that makes the famed Double Cluster, the only known case of a "binary"
cluster, the two -- 7700 light years away -- moving through space
as twins, together since birth. Then look low to the far northeast
to see if you can catch the climbing front bowl stars of
Cassiopeia's opposing figure, the Big Dipper of Ursa