Photo of the Week. Planet Earth: the eleventh of
twelve in the "Flight across Greenland," going from east to west
above the fantastic glacier and a river of ice. See full resolution.
Astronomy news for the week starting Friday, April 25, 2014.
There's not much going on this week unless you like watching
stars and planets move gracefully across the sky. Or unless you
live in Australia or Antarctica, but more about that later. There
is, however, always the friendly Moon, which at the beginning of
our week is in its late waning crescent
phase. The morning of Saturday, April 26, look for it rather well
to the left of
Venus. You might still spot it in morning twilight the next
day. Then it passes through new Moon, though not quite invisibly,
as on the morning of April 29, Greenwich Time, the orbiting Moon
will eclipse the
Sun. But don't make plans to see it happen, as it's visible
as a partial eclipse only in the aforesaid far southern climes of
the Earth. The eclipse is a bit of a curiosity, though, for an
unusually brief annular phase (with the
Moon too far from the Earth to cover the Sun completely, which
leaves a ring of sunlight) that is seen for just six minutes in
Antarctica. Back home, with a good horizon, you can catch the waxing crescent Moon in western twilight
the evening of Thursday, May 1, when it will be passing above Aldebaran in Taurus, the star hard to see. May
1, May Day (actually May Eve), is an astronomical holiday, a
"cross-quarter day" that marks the halfway point from the start of
spring to the beginning of astronomical summer, which begins this
year on June 21.
Leaving the Sun and Moon, it's on to the planets, the usual four,
as
Mercury is completely out of it, passing superior conjunction
with the Sun on Friday the 25th. In western skies as darkness
falls,
Jupiter passes something of a divide by setting at local
midnight (1 AM Daylight Time). Hard to miss among the stars of Gemini, Jupiter is the brightest
thing in the evening sky. But then there is Mars, which is
about a magnitude fainter. Up in southeastern skies in early
evening, the red planet lies well to the northwest of Spica (the two showing off a nice
color contrast, Mars reddish, Spica blue-white) and to the
southeast of Porrima (Gamma
Virginis). It crosses the meridian
to the south around 11:30 PM Daylight Time and does not set until
morning twilight. Further to the southeast, find Saturn. Rising in
evening twilight, the ringed planet crosses to the south around 2
AM amidst the stars of Libra to
the east of Zubenelgenubi
(everyone's favorite star name,
which means "the southern claw" of Scorpius). Venus finishes the parade by rising just
as twilight begins to brighten the sky.
To the southwest of Saturn, find the stars of great Centaurus, the Centaur, one of the brighter and larger constellations. For northerners, much of it is below
the southern horizon. Its sights include the huge globular cluster Omega Centauri and
the closest star to the Sun, Rigil Kentaurus
(the foot of the Centaur), better known as Alpha Centauri. Directly below Libra
prowls Lupus, the Wolf, while to the southeast of
the Scales lurks Scorpius, the Scorpion of the southern Zodiac.
