Astronomy news for the week starting Friday, October 8, 1999.
The Moon passes its new phase this week on Saturday the 9th about
the time of sunrise in the mid-western hemisphere, not eclipsing
the Sun by passing a bit above it. Look for the slim crescent in
western twilight the night of Sunday the 10th. The Moon passes
above Mercury the same night, the little planet practically
invisible in twilight glare, and then north of the star Antares the
night of Wednesday, October 13. The night of Thursday the 14th the
Moon will appear up and to the right of Mars about the time it
passes apogee, its most distant point from the Earth.
This week, on Tuesday the 12th, the red planet, slowly falling
behind the Earth, will pass from Ophiuchus into Sagittarius, the
constellation that holds the winter solstice, where the Sun reaches
its most southerly point on its jouney along the ecliptic. As Mars
descends the southwestern evening sky, it is replaced by bright
Jupiter, which rises in the east shortly after sundown, followed by
dimmer, but still bright Saturn, the pair seen down and to the left
of the rising Great Square of Pegasus.
While hardly visible, Neptune, in Capricornus far to the east of
Mars, ceases its retrograde motion this week and once again starts
its slow easterly trek against the stellar background. The planet
moves so slowly and takes so long to go around the Sun -- 165 years
-- that it has yet to complete a full orbit since its discovery in
1846. Closer Uranus, on the other hand, has turned the Sun two and
a half times since William Herschel found it in 1781, the seemingly
erratic movements of the Uranus leading to the discovery of its
dimmer distant relative Neptune, which gravitationally perturbs
With the Dipper now low in the northwestern sky, Cassiopeia climbs
the northeastern, as the two round the pole opposite each other,
the North Star Polaris and the Little Dipper right in the middle.
Cassiopeia, representing an ancient Queen and mother of Andromeda,
is in a rich part of the Milky Way. As the summer Milky Way, which
cascades down from Cygnus through Sagittarius, slips away, the
autumn Milky Way in Cassiopeia and neighboring Perseus climbs ever
higher, the sight to be with us through much of winter. It's well
worth a drive out of town to dark skies to look. Be watching too
for the ascent of Taurus with its two clusters, the Hyades and the
ever-popular Pleiades or Seven Sisters, the latter rising first
about the same time as Saturn.