Photo of the Week. Blue sky waxing gibbous Moon, 2.1
days past the quarter.
Astronomy news for the week starting Friday, July 26, 2013.
We are certainly into the summer doldrums, with little going on
this week except for the Moon running through its paces. It starts
the week off late in the waning gibbous
phase, then passes third quarter around
noon on Monday, July 29, about the time it sets in the west. The
quarter will make a nice sight in the early morning hours well to
the north of the celestial equator
near the border between Pisces
and Aries. During the rest of
the week it fades as a waning crescent,
not passing new until Tuesday of next week, so you have plenty of
time to admire it.
While all the bright planets but Saturn hover
near the horizon, their visibility is improving. As July turns to
August, Venus
slowly advances toward the end of evening twilight, but is still
difficult to see as it is so low by the time the sky is dark enough
to show it. In the morning sky Jupiter is now
beating out Mars, rising
around 3:30 AM about an hour before twilight commences. Mars
follows half an hour later, but is still difficult to see. Mercury, though,
makes a morning showing. Though it rises after the beginning of
dawn, it's bright and is at its greatest western elongation for the
season on Tuesday the 30th. Of them all, Saturn remains the most
visible. As the month changes, the three are
stacked in southern Gemini to the right
of Castor and Pollux, Jupiter on top, Mercury on the
bottom. In the west (a dozen or so degrees to the east of Spica) as the sky gets dark, the
ringed planet sets just before midnight Daylight Time, leaving us
quite planetless (excluding the outer ones) for over four hours
until Jupiter heaves itself over the horizon.
As the sky darkens, look for Scorpius above the southern horizon, Sagittarius to the east of it, Lupus to the southwest. If you are
far enough south you might spot the fainter stars of Ara the Altar just below the
Scorpion's southern curve. Hercules is then practically overhead, with bright Vega to the east, Arcturus to the west. To the east
of Vega, find Deneb at the tail of Cygnus the Swan or, tipping the figure upside down, at
the top of the Northern Cross. At the head of the Swan, or the
foot of the Cross, is the famed colorful orange and blue double
star Albireo. To the south of
these is Altair in Aquila, the three bright stars
making the Summer Triangle.
Look in the other direction, to the north of Vega, for the
head of Draco, the Dragon, which
then twists between the Big and
Little Dippers.
