Photo of the Week. The Moon, its nighttime side lit
by Earthlight, visits Jupiter, with Venus shining below.
Astronomy news for the two weeks starting Friday, March 16, 2012.
We begin with the Moon in its waning
crescent phase as it moves along toward new Moon on Thursday,
March 22. Your last decent look at it will be in eastern dawn the
morning of Tuesday the 20th. It then pops up very low on the
horizon as a waxing crescent the evening
of Friday the 23rd. The next night will be far better, with the
Moon higher in twilight as it approaches Jupiter. The evening of
Sunday the 25th, we will then be treated with the Moon just to the
right of Jupiter, with Venus watching
from above. Then it gets even better, as the evening of Monday the
26th, the Moon will make a close appearance up and to the left of
Venus, Jupiter now watching from below. Leaving the planetary
scene, the Moon continues to grow as a crescent until it hits first quarter high in Gemini the night of Friday the
30th. In the midst of all this, the Moon passes apogee, where it
is farthest from Earth, the night of Sunday the 25th.
Even without the Moon, Venus and Jupiter together still make for
quite a sight. Having passed each other, Jupiter is now in the
lead and lower down, setting around 10:30 PM Daylight Savings Time, about an hour before
Venus. Though it will keep setting continuously later, Venus
passes greatest eastern elongation (46 degrees) with the Sun the
night of Monday the 26th. Then as Venus goes down, Mars, high in
the sky just south of classical Leo, transits the meridian. It's followed by Saturn. Rising
at the end of twilight still to the northeast of Spica, the ringed planet crosses the
meridian to the south roughly around 2:30 AM. In invisible news,
passes inferior conjunction with the Sun on Wednesday
the 21st, Uranus going
through its own solar conjunction three days later.
It's the Earth that makes
the biggest splash however, as the Sun passes the Vernal Equinox in Pisces on the morning of Tuesday the
20th at 12:14 AM CDT (1:14 AM EDT, 10:14 PM PDT the night of Monday
the 19th), marking the first day of spring in the northern
hemisphere. Barring various subtle effects, the Sun will rise due
east, set due west, be up for 12 hours and down for 12 (giving us
day-night equality). It will also pass overhead at the equator and
technically rise at the north pole
and set at the south
pole. Watch as the rising and setting points rapidly move
toward the northeast and northwest.
With Orion and his Dogs moving off to the west, look
in early evening south and east of Canis Major (marked by shining Sirius) for the bright stars of Puppis, the Stern of the Ship Argo. Above the Larger Dog find the
vastly dimmer stars of modern Monoceros, the celestial Unicorn.