Photo of the Week.. Jupiter in Taurus in November of 2012. The Hyades and Aldebaran are to the right, Pleiades above, southern Auriga to the left.
See Jupiter in
Taurus in 1988-89 and in
2001-02, when the planet also met
up with Saturn.
Astronomy news for the two weeks starting Friday, December 7,
2012.
The holiday season necessitates a series of two-weekers. The next
Skylights will appear December 21, 2012. Thanks for your
continuing interest and patience.
This particular fortnight is also the result of the fine Geminid meteor
shower, which peaks the night of Thursday, December 13 and the
morning of Friday the 14th. Seen for a day or so before and after
the peak, the shower spans Skylights' usual transition time, giving
us a chance to highlight it. Easily as good as August's Perseids,
in a dark sky you can expect a couple meteors a minute that seem to
emanate from the constellation Gemini. The Geminids are the leavings of the
"asteroid" 3200 Phaethon, which is now believed to be a dead
comet. So dress warmly and enjoy the holiday show, which will be
best in the morning hours.
And unless you are surrounded by artificial lighting, the sky will
indeed be dark, as new Moon takes place at the same time, on
Thursday the 13th. Having passed third
quarter on Thursday the 6th, the Moon spends the first week of
our period in morning's waning crescent,
then during most of the second week in evening's waxing crescent, at least until it hits first quarter on Wednesday the 19th, after
which we see a bit of the waxing
gibbous. As the crescent wanes, it will make a fine passage
below the star Spica the morning of
Sunday the 9th, be seen a bit farther below Saturn the following
morning, then end with a delightful passage just below Venus the
morning of Tuesday the 11th. Look for
Mercury down and to the left of them.
Rising just after 5 AM or so, Venus will be a steady guide to
Mercury, which is now sliding down the morning sky toward the Sun (as is
Venus, which is becoming notably lower and dimmer). Going in the
opposite direction, Saturn rises around 3:30 AM in the middle of
our period and is well up in the southeast by the time twilight
begins to light the sky. The evening, for that matter most of the
night, is lit well by
Jupiter. Hard to miss, the brightest starlike object in the
sky until Venus rises, the giant planet continues to hang out in Taurus more or less north of the Hyades and Aldebaran. In minimal planetary
news, Uranus
ends its
retrograde motion and begins moving easterly against the stars
of Pisces just as the Geminid
shower comes to fruition.
We bookend the fortnight with the Sun, which passes two important
points in its apparent celestial motion. At 5:12 AM CST (6:12 EST,
4:12 MST, 3:12 PST) the morning of Friday, December 21st, the Sun
passes its southerly extreme at the Winter Solstice in Sagittarius, beginning astronomical winter and giving
North America the shortest day and longest night. By the time it
rises, as far to the southeast as possible, the Sun will have begun
moving northward toward the Vernal
Equinox and spring. However, because of the Earth's orbital
eccentricity coupled to the tilt of its rotational axis
against the orbital perpendicular, earliest sunset takes place as
we start our period, so that by the time of solstice passage the
evenings will already have begun to lighten.
Rising in early evening, at midnight, mighty Orion stands tall with Gemini up and to the left, Taurus up and to the right, and Auriga above both of these. To the left of him lies Canis Minor, and farther down, Canis Major with Sirius, the brightest star of the sky.
