Astronomy news for the week starting Friday, October 4, 2002.
The crescent Moon slips away into
eastern morning twilight during the beginning of the week, new Moon
taking place the night of Sunday, October 6. Only two hours after
the Moon passes the Sun at new phase, the Moon goes through
perigee, the combination raising especially high tides at the
coasts. The dawning of Friday the 4th sees the thin crescent up
and just a bit to the left of Mars, which is now
rising just as morning twilight is beginning. The following
morning, an even thinner crescent might be seen to the left of Mercury,
the planet becoming more visible toward the end of the week. The
waxing crescent then appears in
the west by the evening of Tuesday the 8th, when it will lie
directly above Venus, which
is becoming more elusive with each passing day.
If last week was "asteroid week," this one is "stationary week"
(especially if one cheats a bit by allowing in next Friday). As
the Earth passes in between an outer planet and the Sun, or as an
inner planet passes between us and the Sun, the relative planetary
speeds seem to make the planet go backwards, or
retrograde, in the
sky. As a planet passes into retrograde, or out of retrograde, it
will appear momentarily "stationary" against the background stars.
On Saturday the 5th, Mercury is stationary passing out of
retrograde, and by odd coincidence, on Thursday the 10th, Venus is
stationary passing into it, at which point it will very rapidly
disappear from the evening sky. Then on Friday, the 11th, Saturn does
the same trick, passing into retro, the planet now rising around
10:30 PM very close to the Taurus-Gemini border
(and yes, weirdly still in Orion!). Wait a bit longer, until 2 AM, and you can
catch the rising of brilliant Jupiter,
ensconced against the dim stars of Cancer to the east of the Beehive cluster.
There is still plenty of time to admire the late summer stars.
Look for bright Vega to the west of
overhead as twilight ends, the star second to Arcturus in northern-hemisphere
brightness, and then only by a hair's breadth. to the east and
southeast of it is the lovely compact set of faint stars that
complete the outline of Lyra, the
celestial Harp. Vega and Lyra are due north of the southern
constellation Sagittarius, which is
now slowly being lost into the southwest. Above and a but west of
the bright star is the head of Draco the Dragon, his "two eyes" bright and obvious.
These stars are now being replaced the classic figures of fall.
Look to the northeast to see the "W" of Cassiopeia climbing upward, the figure followed by the
bright stars of Perseus. To the
east lies the Great Square
of Pegasus, the lines of stars
that make Andromeda going off
to the left.