Skylights featured three times on Earth Science
Picture of the Day: 1
, 2
, 3
, 4
.
Photo of the Week.. Just before sunrise, faint
shafts of rose light shine upward, caused by shadowing light clouds
beyond the horizon.
Astronomy news for the week starting Friday, September 24,
2004.
This is the week of the full Moon,
which takes place on the morning of Tuesday, September 28, just
about the time of Moonset in North America, and since the full Moon
is opposite the Sun, about the time of sunrise as well. With the
Sun just having passed the Autumnal
Equinox in Virgo, this full
Moon will lie just past the Vernal
Equinox in Pisces. The
September full Moon is famed as the "
Harvest Moon." Because the actual time of the full Moon is in
the late morning hours, the rising "Harvest Moon" gets two dates,
the night of Monday the 27th (when the Moon is just short of actual
full phase) and the night of Tuesday the 28th (when it is just past
full). At this time of year, the ecliptic (which the Moon closely
follows) lies fairly flat against the early-evening eastern
horizon. As a result, the delay in nearly-full-Moonrise from one
night to the next is short, a mere half an hour, causing the early
evening to be flooded with moonlight, which in older times allowed
one to work the harvest after sundown.
Other than that, the week's action involves the distant nearly-twin
planets Neptune
and Uranus, the
Moon passing five degrees (about the separation between the two
front bowl stars of the Big
Dipper, which point nicely to Polaris) south of the former on
Friday the 24th, and the same angle south of the latter the next
day, not that it matters much as bright moonlight would make any
observation difficult.
The planetary sky, as over the past weeks, now really belongs to
the morning, with
Saturn (in Gemini) rising
just past local midnight (1 AM daylight time), and Venus
coming up about 3:30 AM Daylight Time. The view of our sister
planet, the second out from the Sun, at 5 or 6 AM is glorious. If
you get up early enough to admire Venus, be sure to look south for
a fine view of Orion and the
stars that will, before long, grace the winter sky.
It is, however, the autumn that now is in full swing, and time once
more to look at Cassiopeia (the
Queen) climbing the northeastern sky, its "W" wonderfully prominent
opposite the Big Dipper. Right between Caph (Beta Cassiopeiae) and Polaris (in
Ursa Minor) is the northern star of
Cepheus (the King), Errai (Gamma Cephei), which hosts
a Jupiter-like planet. The rest of Cepheus, spreads downward in a
large pentagon, and includes such wonders as the variable Delta Cephei and Herschel's Garnet Star (Mu Cephei). Farther
south is the jagged set of dim stars that make the obscure modern
constellation Lacerta, the
celestial Lizard.
