Skylights featured five times on Earth Science
Picture of the Day: 1
, 2
, 3
, 4
, 5
Photo of the Week.. Morning sunlight reflects from
the waters of Lake Michigan, appearing as an upside-down sunpillar.
Astronomy news for the two week period starting Friday,
September 9, 2005.
Skylights is presented for two weeks, and
will resume its regular weekly schedule on Friday,
September 23.
The Moon begins the week just shy of first
quarter, that phase reached on Sunday, September 11. It then
waxes through gibbous to full the
night of Saturday the 17th (about the time of Moonrise), after
which it
wanes through gibbous toward third quarter
(which does not take place until the night of Saturday, the 24th).
The night of Friday the 9th finds the Moon a bit to the west of Antares in Scorpius, while the following night, it will be just to
the east of the bright star. Our companion then takes on Neptune and
Uranus, gliding five degrees to the south of former the night
of Wednesday the 14th, then two degrees south of the latter on
Friday the 16th. The Moon then makes a fine conjunction with Mars the night of
Wednesday the 21st, at the same time falling just to the west of
the Pleiades star cluster in
Taurus. The night of Thursday
the 22nd, the Moon will pass to the north of the Hyades, also in Taurus.
The red planet, rising around 10 PM Daylight Time, remains in
extreme eastern Aries.
Meanwhile, Saturn is
making a nice impact on the morning sky, rising around 3 AM just to
the southwest of the Beehive
Cluster in Cancer.
Mercury then invisibly passes superior conjunction with the Sun (when it is on the
other side of the Sun) on Sunday the 17th.
The real show still belongs to the early twilight evening as Jupiter and
brightening Venus continue to
part from each other, Jupiter setting in mid-twilight, Venus
(shifting to the south) not setting until the sky is fully dark.
On Wednesday the 21st, Jupiter, now moving easterly, finally
catches up with Spica in Virgo, passing three degrees north
of the star.
The Earth makes
its quarterly report at 5:23 Central Daylight Time on Thursday the
22nd (6:23 EDT, 4:23 MDT, 3:23 PDT), this time passing the autumnal equinox in Virgo, at which
moment
astronomical autumn begins in the northern hemisphere (and
spring in the southern). At that time, the Earth's axis is
perpendicular to the line to the Sun, the Sun is on the celestial equator, is overhead at the
Earth's equator, (at least technically) rises due east, sets due
west, is up for 12 hours, down for 12 hours (the interval of
daylight actually extended by a few minutes because of the Sun's
half-degree angular diameter and refraction in the Earth's
atmosphere), sets at the north pole, and rises at the south pole.
Now is the time to admire the Summer Triangle, which in mid evening lies high to the
south and consists of Vega in Lyra (the brightest of the three
stars), Altair in Aquila, and Deneb in Cygnus (the faintest). Nearly in the middle is the
famed double star Albireo, Beta
Cygni.
