Astronomy news for the week starting Friday, October 1, 2010.
Another quiet week, for two in a row. But then the sky is always
a peaceful place to visit, on matter what is going on.
With the last
quarter having taken place last Thursday, September 30, the
week belongs to the Moon's waning crescent,
which stops at new Moon on Thursday, October 7. Your last view of
it will be in dawn on Wednesday, October 6. The morning of Monday
the 4th finds the Moon a bit up and to the right of Regulus in Leo, which is now clearing the horizon. The following
morning look for our companion almost directly below the star.
Just over a day before new phase, the Moon passes perigee, its
closest point to the Earth, thus setting off particularly high
tides (the strength of the tide dependent on the inverse cube of
the Moon's distance from us).
Venus is now leaving us, setting
between sunset and the end of twilight. On Thursday the 7th
(almost exactly as the Moon passes new), Venus enters
retrograde -- westerly motion against the background -- after
which it disappears from view. But early risers take heart, as by
mid-November, the planet will be popping up in the morning skies.
Though Mars sets
later than Venus, it's pretty much invisible in bright western
twilight. And Saturn, having gone
through conjunction with the Sun at the end
of last week, is completely out of it until we see it again in the
morning toward the end of the month.
That of course leaves us with the second brightest of planets (with
the exception of Mars under the most favorable of oppositions),
Jupiter. Rising before sunset, the planet is gloriously
visible in the southeast after evening darkness falls, and now
makes a sort of transition by crossing the meridian to the south at midnight
Daylight Time. Look for it low in the west before dawn.
While the summer constellations are
slipping away to the west, they will still have an evening presence
for some time, reminding us of warmer days. And though they are
dominated by the three figures of the Summer Triangle (Cygnus, Lyra, and Aquila with Deneb, Vega, and Altair), we should not neglect the
set of smaller ancient figures.
Between Deneb and Altair (closer to the latter) find Sagitta the Arrow, which actually
looks like what it represents. Toward the southeast swims Delphinus, the Dolphin, which looks
more like a hand with a finger pointing southward. Farther down in
the same direction is faint Equuleus, the Little Horse, which then leads us to
southwestern Pegasus and the
constellations of autumn.