Astronomy news for the week starting Friday, July 29, 2011.
With new Moon taking place on Saturday, July 30, and with the
ecliptic rather flat against the western horizon, the first decent
look at the thin waxing crescent (in
western evening twilight) will be the night of Tuesday, August 2.
It then heads toward first quarter, the
phase not reached until Saturday the 6th. Mid-week sees some nice
pairings. Look the evening of Wednesday the 3rd to see the
crescent gliding several degrees beneath Saturn, then the
following evening to see the Moon below, but much closer to, Virgo's Spica. As the crescent grows, watch
the fading of the Earthlight on
the Moon's nighttime side (sunlight reflected from Earth to the
Moon and back). On Tuesday the 2nd, our Moon passes perigee, where
it comes closest to Earth.
Saturn has now moved seriously into the west. Though it does not
set until 11 PM Daylight Time, that is but an hour past the end of
evening twilight, so look early, the ringed planet appearing well
to the right of Spica. If you have binoculars, look for the
fainter star Porrima (Gamma
Virginis) just to the right of the planet. Jupiter does
much better, the giant of the Solar System making a transition to
evening by rising near midnight Daylight Time. It's
unmistakable as it cruises the sky below the classic figure of Aries. In the early morning hours,
the scene, the red planet up by around 3 AM. Just barely first
magnitude, Mars is moving swiftly eastward between the classical
figures of Taurus and Gemini. Compare its color to the
colors of Aldebaran in Taurus
and Pollux in Gemini (the latter
the southeastern and brighter of the Castor-Pollux pair). Close to the Summer Solstice, the planet is about
as far north as it ever gets.
'Tis the season for the Summer
Triangle. Seen high in the east in early evening hours,
crossing the meridian around midnight,
it is made of Vega in Lyra at its northwest apex, Deneb in cyg-p.html">Cygnus at the
northeast, and Altair in Aquila at the southern extension.
Falling between Cygnus (see the Swan upside-down as the Northern
Cross) and Aquila find a pair of exquisite ancient figures, Sagitta, the Arrow (which indeed
looks like what it is supposed to represent), and Delphinus, the Dolphin (which appears
more as a human hand with a finger pointing south).