Photo of the Week. Ranks of light clouds cast
shadows on the mountainous Earth below.
Astronomy news for the week starting Friday, June 22, 2007.
We begin our week with the first quarter
Moon, the phase passed on Friday, June 22, rather well before
Moonrise in North America. By evening, you might note the Moon
very slightly past its formal quarter, or "half-Moon" state
("quarter" referring to the quartering of the
orbit). The whole week is thus spent in the waxing gibbous phase, as full is not reached until Saturday, June 30.
The night of Wednesday the 27th, the Moon will pass just to the
south of Antares in Scorpius, these two with
Jupiter up and to the left all in a very nice line (the
brightness of the nearly-full Moon making Antares a bit difficult
to see). By the following evening, the Moon
will be well below, to the southeast of, the giant planet.
Though setting earlier each night (now just after 11 PM Daylight
Time), Venus
's brilliance continues to increase as it totally dominates the
early evening sky. Not far to the east of it lies Saturn
(which itself still lies to the west of Regulus in Leo, the two closely tracking the local ecliptic). The week leads up to
a lovely conjunction between the two planets. Watch as they get
ever closer, the crossing between them to take place on Sunday,
July 1, when they will be but 8/10 of a degree apart. Saturn thus
also sets just past 11 PM Daylight, about as Jupiter is transiting
the meridian to the south. Jupiter is
then with us nearly all night, not setting until mid-dawn. In the
morning sky, try now to find Mars,
which rises near the Pisces-Aries border about 2 AM just to the
north of east.
Then, though hardly naked-eye events, Uranus
(just below the Circlet of
Pisces, but across the border into Aquarius) enters retrograde motion on Saturday the 23rd, while
Mercury passes inferior conjunction with the Sun on Thursday
the 28th, when it flips from the evening sky into that of the
morning.
As the Sun moves
through Gemini to the east of
the Summer Solstice, it will slowly
encroach on Cancer and then on that
harbinger of northern Spring, Leo,
which (seeming to shove Saturn before it) appears now to stalk
toward evening twilight. Trailing behind along the ecliptic are Virgo (with Spica), Libra, and then Scorpius, and we are back to Antares
and Jupiter.