Photo of the Week. Filigree clouds are framed by the
blue sky.
Astronomy news for the week starting Friday, July 24, 2009.
The waxing crescent Moon climbs out of
twilight during the early part of the week, culminating in first quarter on Tuesday, July 28th, shortly
before sunset, allowing you to see the near-perfect phase during
the late daylight hours with the Moon approaching
the meridian to the south. It will
thereafter begin to wax in its gibbous
phase as it heads toward full phase late
next week. On the evening of Friday the 24th, the crescent will
appear several degrees below Saturn, while the
following evening it will shine to the left and a bit down from
the ringed planet. On the evening of Thursday the 30th, look for
the Moon to the west of Antares
in Scorpius.
Saturn, setting just after twilight ends, is slowly being lost to
the evening sky. We make up for it with bright Jupiter, which is now rising unmistakably in
the southeast before twilight draws to a close. Moving slowly
retrograde in northeastern Capricornus, the giant planet is just a couple degrees
north of third magnitude Deneb
Algedi (Delta Capricorni), which is a prominent part of the
figure.
Then stay up late to watch the 2 AM rising of Mars followed
an hour later by that of Venus. The two
planets are now in a wonderful setting of the sky. On the morning
of Monday the 27th, the red planet will pass five degrees north of
Aldebaran in Taurus, and of course will during
the week be seen north of the Hyades cluster and to the southeast of the Pleiades as well. At the other
end of Taurus, Venus makes a close pass to third magnitude Zeta Tauri, the star that marks the
eastern horn of the celestial Bull. The color contrast between
Venus and Mars is remarkable, as is the similarity between that of
Mars and Aldebaran.
Back in the evening, Mercury is making a dim
appearance very low above the western twilight horizon.
The celestial Scorpion, which the Moon will pass through at the end
of the month, is one of the few constellations that really does look
like its name. If you have a clear southern horizon, look for the
curve of stars that lies to the south of Antares that swings up
again in the tail, which ends at a little two-star asterism called
"the Stinger." Down and to the right of the Scorpion, note the
bright blue stars of Lupus, the
Wolf.
