Astronomy news for the week starting Friday, March 11, 2011.
Note: After the beginning of Daylight Savings Time on Sunday, March 16,
add an hour to the times given below.
The growing Moon continues going through its paces, starting our week
just barely shy of first
quarter, that phase properly reached the evening of Saturday,
March 12, about the time of sunset in North America with the Moon
close to the meridian. Since the Sun
is just short of the Vernal
Equinox, the early-evening quarter will be high in the sky as
it bears down on the Summer
Solstice between the classical figures of Taurus and Gemini. Look for orangish Aldebaran to the right of the
quarter, Castor and Pollux to the left. The Moon then
enters the waxing gibbous phase, which
will occupy the rest of the week, full
Moon not passed until next Saturday. Watch its descent to the
south as it nears the autumnal
equinox in Virgo.
Jupiter escapes ever more
into evening's light, the giant planet having made the transition
to setting shortly AFTER the end of dusk. But while doing so, it
also helps make for the week's biggest event as it passes
conjunction with Mercury
(barring Pluto, the largest
and smallest planets getting together), Mercury just two degrees
north of the Lord of Planets. The pairing provides a fine way of
locating the little one. Look first the evening of Sunday the 13th
in fairly bright twilight. Given a good horizon, you will see
Mercury just down and to the right of Jupiter. With Mercury coming
night-to-night upward and Jupiter going oppositely, over the next
three nights watch as the two switch places: by the evening of
Wednesday the 16th, Mercury will then be nicely UP and to the right
of Jupiter.
Jupiter thereafter more or less disappears, to be replaced by Saturn, which now RISES as
evening twilight draws to a close. With us all night, Saturn
crosses the meridian to the south (still to the northwest of Spica) around 1:30 AM, and does not
set until after sunrise. Look to the west for it and Spica in the
hours before dawn. Then there is Venus. Stuck for the last month rising around
4:30 AM, the ever-earlier beginning of morning twilight has finally
caught up with it, the rising of the brilliant planet just barely
beating it out. No matter, Venus is so bright that you can still
find it glowing in the southeast even shortly before sunrise.
While the spring stars, Leo and
Virgo included, have made their entries into evening, if you look
far enough to the north you can still spot the constellations of late autumn. Look in
particular above Orion (itself to
the west of the meridian in early evening) to bright Capella in Auriga, thence to the west to spot the star streams of
Perseus, the hero of the Andromeda myth.
