Skylights featured three times on Earth Science
Picture of the Day: 1
Photo of the Week.. Trees exalt the contrasting sky.
Astronomy news for the week starting Friday, October 1, 2004.
Our Moon, having just passed full, spends most of the week in its
waning gibbous state, rising ever later after
sundown, while not reaching
third quarter until the morning of Wednesday, October 6. Less
than a day before the quarter, it passes apogee, where it is just over five percent farther from
us than average (the effect not noticeable with the naked eye).
With the Sun still not far from the Autumnal Equinox, the third quarter will be just a bit
beyond the Summer Solstice, in Gemini, and will be seen quite high
in the sky around the time of sunrise.
The morning sky still hosts the visible planets, though Saturn
now actually rises just before local midnight (1 AM daylight
time). Watch the Moon pass to the north of it the morning of
Thursday the 7th. Only a month ago, Saturn passed conjunction with
Venus. Though both are moving east against the stars, Venus --
keeping close pace with the Sun -- is moving much the
faster, causing the two planets to separate in angle. While Saturn
rises ever earlier, Venus rises ever later, not coming up now until
around 3:30 AM Daylight Time (still plenty early enough to be high
in the east in growing morning twilight). And while Saturn is in
Gemini, Venus has shifted a full constellation over. Around noon
on Sunday October 3 Venus will pass conjunction with Regulus in Leo. Watch in the dark hours before dawn that same
morning to see the two only a quarter degree apart (half the
angular diameter of the Moon), Venus vastly the brighter.
And while Venus takes top honors, Mercury
hides, passing superior conjunction with the Sun on Tuesday
the 5th. Jupiter
is still obscured by the Sun's glare as well, but will soon be
making a morning appearance.
Early October evenings still feature the grand Summer Triangle. Deneb (in Cygnus), at the northeastern apex of the Triangle, is
nearly overhead in moderate latitudes, while bright Vega in Lyra shines a bit off to the northwest, and Altair (in Aquila) to the south. Among the most exquisite of
constellations, Lyra is primarily made of a nearly perfect
parallelogram of stars. Off by just a small angle to the northeast
of Vega is the famed double-double star Epsilon Lyrae. If you can see the
widely spaced pair (each of which is again seen double in a
telescope), your vision is exceptionally good. Three fainter
constellations cascade to the south more or less in between Aquila
and Cygnus: faint modern Vulpecula
(the Fox), Sagitta (the Arrow), and
Delphinus (the Dolphin), the latter
again made of a parallelogram with a fifth star sticking out to the
southwest, making the figure look like a hand with a finger
pointing down toward Sagittarius.