Astronomy news for the week starting Friday, March 9, 2012.
Daylight Savings Time begins Sunday, March 11. All times below are
standard. Add one hour for DST.
Having just come off of full phase, the
Moon wanes this week, first in its gibbous phase and then, after achieving its
third quarter on the night of Wednesday,
March 14, as a fat crescent.
The night of Saturday the 10th, the Moon will pass six degrees
south of
Saturn, the planet, the Moon, and the star Spica (to the southwest of Saturn)
making a fine triangle. On Saturday the 10th, the Moon will pass
through its perigee, where
it is closest to Earth (but only by about five percent).
The prize of the week is the conjunction between the two brightest
planets,
Venus and
Jupiter. Formal north-south conjunction actually takes place
the morning of Thursday the 15th, with the pair out of sight. But
a few days earlier are actually better for viewing, the two getting
to within three degrees of each other and not setting until 10 PM.
Look in western evening twilight during our week to see brighter
Venus on the right, Jupiter on the left. After this grand display,
Jupiter will sink evening-by-evening toward the horizon, while
Venus will continue to gain in altitude and brilliance throughout
the month and all of April.
That leaves
Mercury, which sets at the end of evening twilight, Mars,
and Saturn.
Having passed opposition with the
Sun, Mars, rivaling the brightest stars,
is now well up in the east as the sky darkens, to
the south of the classical figure of Leo and several degrees to the east of the star Regulus. The ringed planet then
rises at 9 PM or so, as noted above to the northeast of Spica, both
in Virgo, the next constellation of the Zodiac to the
east of Leo. Mars next crosses the meridian to the south a half hour before midnight,
while Saturn does the same near 2:30 AM, the pair making another,
though far more separated, sight.
Orion and his gang are now slowly
escaping to the west, but are still eminently visible. As they
shift along, look for the bright stars of Puppis, the Stern of Argo, down to the south and east of Canis Major, which is instantly
recognizable by the brightest star in the sky, Sirius.
