Skylights featured three times on Earth Science
Picture of the Day: 1
, 2
, 3
, 4
.
Photo of the Week.. Storm clouds cover the distant
sky, their promise always to clear to give a view of the stars.
Astronomy news for the week starting Friday, Octoer 3, 2003.
The Moon waxes through its gibbous phase the early part of the
week, and reaches full the night
of Thursday, October 9. While for the stargazer, full Moons are a
bit of a nuisance since they blot out the fainter stars, this one
should be admired as being a bit special. First, the exact phase
(as exact as it can get without producing an eclipse, this full Moon passing below the
Earth's shadow as a result of lunar orbital tilt) takes place
shortly after midnight, with the Moon fairly high in the sky amidst
the faint stars of Pisces. The
exact times are 3:27 AM EDT, 2:27 CDT, 12:27 PDT. Second, this
full Moon is the one of the two with the most famed of names, the
"Harvest Moon" the one in September that is closest to the passage
of the Sun across the autumnal equinox, the October full Moon the
"Hunter's Moon." These are special because the evening ecliptic,
near which the Moon moves, has a shallow angle to the horizon, and
therefore the delay in moonrise from one night to the next is
short, giving us a great deal of early evening moonlight -- perfect
for being outside after dark.
As the Moon moves along its path, it confronts three planets,
passing south of Neptune the night of Saturday, October 4, south of
Uranus the morning of Monday the 6th, and finally great Mars during daylight also on the 6th. The waxing gibbous
Moon will therefore be to the west of the red planet the night of
Sunday the 5th, and to the east of it the following night, the
juxtaposition allowing easy note of the lunar orbital motion. The
Moon will actually occult, or pass over, Mars from New Zealand and
Antarctica.
Other planets are taking the stage. Begin to watch for
Venus in west-southwestern twilight. Then about an hour after
Mars transits the meridian to the south (around 10 PM Daylight
Time), Saturn
rises with the confines of Gemini. And just under an hour after Mars sets (about
3:30 AM),
Jupiter rises to dominate morning twilight. Watch it rise and
then disappear into a brightening sky. With excellent eyes and
under superb conditions, the planet can actually be seen in
daylight (as, of course, can Venus).
By 9 PM, Sagittarius is now
slipping well into the southwest as we say a fond goodbye to the
summer constellations. Look for the upside-down "Little Milk
Dipper" that lies in the heart of the Milky Way. To the north, Cygnus and the like will last longer, actually into
winter. Moderately high to the south in late evening, see the Great Square of Pegasus, below
which, in Pisces, is the vernal equinox, which the Sun will
pass on the first day of spring of next year. For now, enjoy the
autumn stars, the Great Square followed in the sky by Taurus the Bull and its two great
star clusters, the Pleiades
and Hyades, the latter making
the vee-shaped head of the great beast.
