Skylights featured three times on Earth Science
Picture of the Day: 1
Photo of the Week.. A peaceful crescent Moon sets in
the west, Earthlight barely
Astronomy news for the short week starting Friday, September 5,
The Moon waxes through its gibbous phase
most of the week, reaching full around noon on Wednesday, September
10. It will therefore be just shy of full when it rises the night
of Tuesday, the 9th, just past the phase at Moonrise on Wednesday.
The night of Sunday the 7th finds the Moon in the middle of the
"cocked hat" figure of Capricornus
(having passed south of
Neptune during the day). The following evening (Monday, the
8th), the Moon will skirt south of
Uranus, and will be found to the west of Mars.
Passing the red planet during the day (and occulting it for part of
the eastern hemisphere), the Moon will then be found to the east of
Mars the night of Tuesday, the 9th.
Having passed opposition with the Sun, Mars is now rising
before sunset, is well up in the southeast at the end of evening
twilight, and is also crossing the meridian to the south before
local midnight (about 12:30 AM Daylight Time).
Retrograding -- moving westerly against the stars -- it is
approaching Uranus, but cannot quite reach it to make a second
conjunction for the year (the first and only occurring last June
20th). The red planet starts the year off brilliantly, at
magnitude -2.9 (3.8 times brighter than the brightest star, Sirius), fading only to -2.1 by the
month's end (still 1.8 times brighter than Sirius).
About an hour after Mars's meridian passage, Saturn
rises in the northeast, beautifully tucked within the elongated box
that makes the classical figure of Gemini, the ringed planet almost as far north as it can
get. The other planets are effectively out of sight,
Mercury passing inferior conjunction with the Sun on Wednesday,
the 10th, when it is more or less between us and the Sun (not
About as Saturn rises, so does Betelgeuse in Orion, a reminder that northern
summer is slowly coming to an end as the stars of winter begin to
press upon us. It is still summer, however, and early September is
a fine time to catch the summer stars, as they wheel overhead and
to the south as twilight falls, though Moonlight will get in the
way. Look about halfway up to find Altair in Aquila, the Eagle, its two flanking stars looking like
winglights on an aircraft (for which the trio has been taken).
Down and a bit to the west is one of the more prominent "modern" constellations, Scutum, the Shield, which holds an especially prominent
part of the Milky Way.
You will have to go to the country and wait for the Moon to move on
to see the Milky Stream, however. Directly below Scutum is the
Little Milk Dipper of Sagittarius,
which from a latitude of 30 degrees south (the southern tip of
Africa, southern Australia, central Chile and Argentina) passes