SKYLIGHTS
Astronomy news for the week starting Friday, October 12, 2001.
Our Moon passes through its new phase this week, on Tuesday the
16th. As the crescent wanes and descends the early morning sky, it
will stand directly above brilliant the morning of Sunday the 14th,
and down and to the left of the planet and close to the horizon in
dawn the morning of Monday the 15th. The Moon will then make its
first appearance in the western evening sky as a slim waxing
crescent the night of Wednesday the 17th. At the time of both
crescents be sure to admire the Earthlight on the Moon, light
reflected from Earth that lights up the Moon's nighttime side.
Mars continues to hang out in the post-twilight southwestern sky,
as it will for the rest of the year, while Saturn and Jupiter
encroach ever more into the late evening before midnight, Saturn
now rising in Taurus shortly after 9 PM Daylight Time, Jupiter,
smack in the middle of Gemini, about two hours later. Still-bright
Mars is moving out of Sagittarius and into Capricornus, and will
pass Neptune early next month. The planetary sky, however, more
belongs to events you cannot see that involve the planet closest to
the Sun and the one (excepting tiny Pluto) farthest from the Sun:
little Mercury goes through inferior conjunction, when it is more
or less between us and the Sun, on Saturday the 13th, and Neptune,
in Capricornus, begins its retrograde motion on Wednesday the
17th.
The debate about Pluto's status as "planet" continues unabated.
Now well north of the ecliptic path in southern Ophiuchus and
nearing conjunction with the Sun, the small body -- about the size
of the Western United States -- has as much in common with a slew
of even smaller bodies in the "Kuiper Belt" of comets that extends
from just beyond Neptune's orbit to well outside Pluto's. Pluto is
the largest of them, and could be considered a transition object,
so in a way it is both, a planet and a Kuiper Belt object (a "KBO"
in the trade) at the same time, so everyone can feel
satisfied.
Look down and to the right of Mars for a last admiration of
Sagittarius and its five-star "Little Milk Dipper," which as autumn
advances will slip into evening twilight. It and its summer cohort
are now being replaced by the full autumn sky, the Great Square of
Pegasus well up in early evening and crossing the meridian to the
south around 11 PM, by which time we easily see Taurus and its two
clusters: the Hyades (which make the Bull's Head) and the charming
"Seven-Sisters," the Pleiades, which at first look like a fuzzy
little ball until closer scrutiny resolves them into a small host
of stars, the object brilliant in binoculars.
