Astronomy news for the week starting Friday, August 28, 2009.
The Moon waxes through its gibbous phase this week, as it heads toward
full on Friday, September 4th. The
night of Thursday, the 3rd, the not-quite-full Moon will thus rise
just before sunset. The evening of Friday, August 28th, finds the
Moon well to the east of Antares
in Scorpius and above the
Scorpion's two-star Stinger. Then the last day of the month, the
Moon passes apogee, where it
is farthest from the
Earth.
The night of Thursday, September 1st, finds the Moon a bit to the
west of Jupiter, while the following night it will be closer, but
to the northeast of the giant planet. Several hours after the Moon
passes Jupiter, it zooms past and to the north of
Neptune. Jupiter plays games with this very distant planet.
Last May, Jupiter passed Neptune while going easterly, then when it
entered a faster
retrograde motion (the result of the Earth passing between it
and the Sun), Jupiter
passed the god of the sea again in July going west, making Neptune
now to the east of Jupiter. Once Jupiter resumes its normally
easterly motion, they will pass again next December 19.
In the evening,
Saturn and Mercury
are truly out of sight, both awaiting conjunction with the Sun.
Too bad too, as on Friday the 4th, the Earth passes through the
plane of the rings (which it does twice every Saturnian orbital
period of 29.5 years), and the ultrathin rings disappear from view.
But Jupiter rescues the night. Now well up in the southeast at the
end of twilight, it passes the meridian to the south at midnight
Daylight Time. Then, a bit over an hour later, around 1 AM
Daylight, up comes
Mars as it enters southern Gemini. Not to be outdone,
Venus next rises on the scene around 4 AM, still unmistakable
in its brilliant glory. Though rising ever later, it still
announces itself over an hour before the beginning of twilight, in
Cancer, this week passing beneath
the Beehive Cluster (making a
fine opportunity to find the rich set of stars with
binoculars).
One of the giant constellations of
the sky now falls to the southwest in early evening. Ophiuchus, the Serpent Bearer (and
the embodiment of medicine), entwined in mythology by Serpens, the Serpent (which comes
in two parts, Serpens Caput the Head, to the west, and Serpens
Cauda, the tail, to the east), stands as a huge rough pentagon to
the north of Antares. Above him, to the north, lies Hercules, the great Greek Hero of
ancient times.
