Skylights featured three times on Earth Science
Picture of the Day: 1
, 2
, 3
, 4
.
Photo of the Week.. A crimson sunrise is enhanced by
a red sunpillar, caused by reflection of sunlight from ice crystals
in the clouds.
Astronomy news for the week starting Friday, January 14, 2005.
While last week was about as busy as could be, this week is quite
the opposite, nothing much actually "happening," which is not bad
since it allows one simply to enjoy the quiet sky. One "big
event," such as it is, is that we begin the week with the Moon in
its waxing crescent phase moving through Aquarius and Pisces,
then passing its first
quarter about midnight the night of Sunday the 16th, about the
time of Moonset in North America. The rest of the week sees the
Moon in its waxing
gibbous phase climbing northward toward Taurus and Gemini.
The night of Wednesday the 19th, the Moon will lie close to the Pleiades star cluster in Taurus,
though its brightness will make the cluster's stars hard to see.
The passage reveals just how angularly small the Moon really is.
Though the Pleiades seems small to the eye (a bit over a degree
across), you could "fit" two full Moons across it! The Moon's
apparent large angular size is but an illusion (as anyone who tries
to photograph a Moonrise with an ordinary camera quickly
discovers).
The planetary week begins with
Mercury and
Venus still in close companionship, only half a degree apart,
but now closer to the horizon in morning twilight and more
difficult to see, the pair not rising until after dawn begins.
Much more readily visible is Mars. Moving quickly to the east against the background
stars, the planet now lies rather well to the east of Antares in Scorpius, the color similarity quite obvious. Though
Mars is just now crossing the boundary from second to first
magnitude, Antares is still a bit over half a magnitude (65
percent) brighter. Now a bit to the west of the meridian at dawn
find Jupiter,
which -- though Venus is brighter -- still dominates the sky, the
giant planet now rising shortly before midnight. The prize for
best visibility still goes to Saturn.
Having just passed opposition with the Sun, and rising just before
Sunset, the planet is with us practically all night, shining
brightly in Gemini to the south
of Castor and Pollux, the trio making a truly
lovely celestial sight. If you have a new telescope, by all means
take a look at the planet to admire its wide-open rings. Nearby
will be a tiny "star," Saturn's largest satellite Titan, which is
the focus of the Cassini-
Huygens space probe.
Perhaps the best sight is Comet Machholz. Just visible to the naked eye
(and far better in binoculars), this visitor from the frozen depths of the
Solar System will spend the week passing against the stars of
Perseus.
Standing directly north mighty Orion is one of the brightest constellations of the
sky, Auriga, the Charioteer,
which contains the most northerly "first magnitude" star, Capella (the "She-Goat") which -- as
sixth brightest in the sky -- actually ranks as magnitude "zero."
Right next to it is a thin triangle of stars that represent her
"kids." In the faint Milky Way near the Auriga-Taurus boundary is the Galaxy's "anticenter,"
where we look directly away from the Galactic nucleus in Sagittarius, the latter home to a
gigantic
black hole of over three million solar masses.
