Astronomy news for the week starting Friday, October 23, 2009.
Our Moon
starts us off with its fat waxing
crescent phase. It then reaches its first quarter on the night of Sunday, October 25,
about the time of sunset in North America with the Moon high to the
south. Just two hours before the quarter, it passes apogee, where it
is farthest from the Earth, the combination
with the quarter giving an especially low tidal swing (between high and low tides) at the
coasts. The remainder of the week -- of the month for that matter
-- is spent in the waxing gibbous
phase.
The Moon then takes on three planets. It first passes north of Jupiter after they
both set the morning of Tuesday the 27th. Look the evening of
Monday the 26th to find the Moon just to the northwest of the giant
planet and then to the east of it the following evening. Then the
evening of the 27th, the Moon will glide north of Neptune, and as the
week ends, on the morning of Friday the 30th, it slides well to the
north of Uranus.
Aside from the Moon, the evening hours are dominated by Jupiter,
which crosses the meridian to the
south now about 8 PM Daylight Time and does not set until 1 AM. In
between,
Mars, which is rapidly encroaching on the scene (in Cancer, heading toward the Beehive Cluster), rises an hour
before Jupiter goes down, pretty much right at midnight. It'll
fade into twilight before it transits to the south. By then,
though, Venus is
up, the second planet from the Sun making a bit of a transition by
rising right at dawn (just before 6 AM). Its brilliance still
makes it visible in a brightening sky. As Venus descends day-by-
day toward the morning horizon, Saturn separates
from it by rising ever earlier, about 4:30 AM, just over an hour
before Venus. Moving easterly against the stars, the ringed planet
has now made the transition from Leo to Virgo, and is
positioned just to the north of the Autumnal Equinox.
The autumn constellations are of
course full upon us now. Look to the east in early evening to
admire the Great Square of
Pegasus, as the Flying Horse
climbs the sky. By late evening it is soaring across the meridian
to the south. Below it is the Circlet of Pisces, which lies just to the northwest of
the psc-w-t.html">Vernal Equinox. Farther down you can see
lonely first-magnitude Fomalhaut of Piscis Austrinus (the Southern Fish), which has been
found to be orbited by a distant planet. Farther down yet, the modern
constellation Grus, the Crane,
stalks across the southern horizon.
