Photo of the Week. Striking ripples in the clouds
reveal atmospheric waves.
Astronomy news for the week starting Friday, January 26, 2007.
We begin the week with the Moon just past its first quarter and
in the waxing
gibbous state, which grows until full Moon is
reached on the night of Thursday, February 1, around midnight in
North America, allowing you to see it full-on at its highest point
in its daily arc across the sky as it anticipates Groundhog Day on
Friday, February 2. On the night of full phase, Thursday the 1st,
the Moon will lie just to the west of Saturn, the Moon,
Saturn, and Leo's Regulus all in a fine row. Watch
them as they rise in early evening.
The western evening twilight sky now holds both the inferior
planets (so called because they are closer to the Sun than Earth,
in old fashioned terms being "below" the Earth). Look for Venus in the southwest after sundown. Because of
the planet's brilliance, you won't have to look too hard. Then
before Venus gets too low, look several degrees down and a bit to
the right to find Mercury, which is heading
toward greatest eastern elongation on February 7. About half an
hour before Venus sets (just after twilight ends around 6:45 PM),
Saturn rises almost due east followed by Regulus, and is then with
us all night long, crossing the meridian to the south about 1 AM.
Two and a half hours later, around 3:30 AM,
Jupiter then joins the ringed planet in the sky. Lording over
the southeastern sky, Jupiter does not finally fade away until
bright twilight takes over. Look for Antares to the southwest of the
bright planet. Mars,
whose rising still tracks the onset of dawn, remains tough to find.
The most northerly constellations of the Zodiac are now on fine display.
Look for Taurus to cross the
meridian high to the south around 8 to 9 PM, with Gemini following an hour or two
later. The Summer Solstice lies
between the two constellations, classically in Gemini, technically
just over the artificial border (drawn up in the 1920s) into
Taurus. Each has a first magnitude star to admire, Taurus holding
Aldebaran (seemingly surrounded
by the more distant Hyades cluster), Gemini holding Pollux. Gemini also contains the
brightest second magnitude star (sextuple Castor), while Taurus has Elnath, the Bull's northern horn and
number five in the second-magnitude category. Elnath is properly
the Beta star, while Castor, dimmer than Pollux, was made Alpha
Gem. Elnath connects Taurus with more northerly Auriga, and also carries the no-
longer-used name Gamma Aurigae.