Photo of the Week. Tranquility. (See the water's
beauty at full resolution.)
Astronomy news for the week starting Friday, December 12, 2008.
Specific "phases of the moment" still bracket the week. We start
it off on Friday, December 12, with the Moon at full phase, rising near sunset, setting
near sunrise. It then wanes through the gibbous phase until it hits third quarter the morning of Friday the 19th
with the Moon about crossing the meridian to the south as seen from North
America. If you are on the coast, watch for especially high
tides early in the week, as the Moon will also be near perigee, where
it is closest to the Earth. As it wanes, our Moon visits Saturn,
crossing well to the south of it the night of Thursday the 18th.
With the Sun close to the Winter
Solstice in Sagittarius, this
full Moon will be the highest of the year.
Though waning, the Moon will still be bright enough to drain much
of the charm out of one of the best meteor showers of the year, the
Geminids. A product of dead Comet
Phaeton (once thought to be an asteroid until its orbit was
connected to the shower), the meteors seem to come from the
constellation Gemini, this
"radiant" a product of the meteoroids' motions combined with the
movement of Earth through the swarm. The shower peaks the night of
Saturday the 13th (and the morning of Sunday the 14th). The shower
normally produces well over a meteor per minute. Even with
Moonlight, you might still see some of the brighter ones.
Though the great conjunction is over, Venus and Jupiter still
dominate southwestern twilight skies, with brilliant Venus now
notably to the east of Jupiter, making planetary motion really
obvious. Jupiter, however, is slowly disappearing, now setting
about an hour after the end of twilight, while Venus, climbing
rapidly northeasterly through the Zodiac, does not set until near 8
PM. Moving into evening, Saturn now rises east of Regulus by 11:30 PM, almost exactly
as Uranus
sets, the two near opposition with each other.
The late autumn stars are in full evening glory. Look for Andromeda high overhead as seen from
northern climes to the northeast of the Great Square of Pegasus. To the northwest of the sweeps of stars that
make Andromeda, find the fuzzy Andromeda Nebula, Messier 31, a nearby galaxy more than
two million light years away that is the most distant thing to be
seen with the naked eye. To the southeast of Andromeda lies the
simple constellation of Triangulum,
and farther down, the first constellation of the classical Zodiac,
Aries, the Ram. If you are an
early riser, the Big Dipper is
nearly overhead just before dawn.
