Astronomy news for the week starting Friday, October 21, 2011.
The Moon fades away this week from just-past-third-quarter through its waning crescent phase towards new, which it
will hit on Wednesday, October 26, when it switches from the
morning sky into evening. Your last look at the thin waning
crescent may be had shortly before sunrise the morning of Tuesday
the 25th, while the first glimpse of the thin waxing crescent will be during evening twilight on
Friday the 28th.
Look the morning of Saturday the 22nd to see the Moon rising well
below Mars with Regulus
of Leo just up and to the left of
the crescent. Then, though the sight will be quite invisible, the
night of Thursday the 27th, the Moon will pass to the south of both
Venus. The Moon will actually occult (pass directly over)
Mercury as seen from areas of the south Pacific. Just 8 hours
before new Moon, the Moon passes
perigee, where it is closest to Earth, the combination bringing
especially high and low tides to the coasts.
Jupiter and Mars still provide the planetary
show. At opposition to the Sun next Friday the 28th, Jupiter rises
just after sunset, is nicely up in the east by the time the sky is
dark, and is with us all night, crossing the meridian to the south around local
midnight (1 AM Daylight Time). The planet is so bright (minus-
third magnitude) that it is drawing considerable public attention.
About half an hour after Jupiter moves into the sky's western half,
Mars, now scurrying toward the Sickle
of Leo, rises, the orangy-red color of the planet making a nice
contrast with blue-white Regulus.
Watch too for the Orionid meteor shower (the
Halley's Comet), which seems to come out of Orion and peaks the night of Friday
the 21st and the following morning. Though it typically produces
some 20 meteors per hour, the near-quarter-Moon will significantly
interfere with the event, washing out the fainter meteors.
Look in late evening for the large box of stars that makes the Great Square of Pegasus. Coming off the northeast
corner are the graceful curves of stars that make up Andromeda of the eponymous myth.
Directly south of the Square will be the distorted circle of stars
that forms the "Circlet" of Pisces, down and to the left of
which is the Vernal Equinox, the
point that the Sun passes over in March to begin astronomical
spring, which, as we deepen into Autumn, now seems so far away.