The Sky This Month – March 2013

CometPanSTARRSThe sky this month features Comet C/2011 L4 (PANSTARRS) as it swings around the Sun and finally reveals itself to northern observers.  While the comet isn’t quite living up to expectations, it should still become easily visible in binoculars and possibly with the unaided eye.  For northern observers, the comet lies about a fist-width above the western horizon just after sunset.  It becomes most accessible from March 8-20.  And while most planets including Mars and Venus this month are obscured by the Sun, Jupiter and Saturn continue to present excellent targets for stargazers.  Saturn’s rings, in particular, lie at a lovely tilt and present the best view in years for observers with a small telescope.  Here’s what to see in the sky this month…

1-2 March.  Rising just before midnight, the planet Saturn spends tonight and tomorrow about 5º from the waning gibbous Moon.  Saturn lies in the constellation Libra right now, so it’s south of the ecliptic and better positioned for southern observers than for northern observers.  But all observers with small telescope will be rewarded by an excellent view of the rings which are tilted by some 19º from edge-on, providing a dramatic view of the planet.  With the tilt, you can also better see structure in the rings, especially the dark gap of the Cassini division which separates the wide inner “B” ring from the outer “A” ring.  Saturn is visible in the eastern sky in the early morning hours this month.  For those who need sleep, remember the planet will rise a litter earlier each night and become visible during honest hours in May through August.

4 Mar.  Last-quarter Moon, 21:53 UT.

8-20 Mar.  Southern stargazers have been following Comet C/2011 L4 (PANSTARRS) in the early morning sky for the past few weeks.  Now northern observers get a chance.  PANSTARRS should be brightest from March 12-18.  At one time, astronomer predicted the comet would reach magnitude -1.0, nearly as bright as the star Sirius.  But right now, it looks like it will only get to magnitude +3.0.  That’s still bright enough to spot in binoculars in twilight sky, and you might even see it without optics.

The comet emerges low in the western sky on March 8 about 30-45 minutes after sunset, then appears to rise slightly and slide northward along the horizon in the twilight sky for the next few weeks. It makes its closest approach to Earth on March 5 when it lies about 1.10 AU from Earth.  The comet’s closest approach to the Sun on March 10 takes it inside the orbit of Mercury.  PANSTARRS should show a tail by this date.  On March 12, the comet will lie close to a slender crescent Moon after sunset… a good photo-op.

Where to find Comet PANSTARRS in the western sky after sunset, as seen from 40 N latitude.  If you are north of this latitude, the comet will appear slightly lower in early March and higher in later March than shown here.  (Image credit: SkyandTelescope.com)

Where to find Comet PANSTARRS in the western sky after sunset, as seen from 40 N latitude. If you are north of this latitude, the comet will appear slightly lower in early March and higher in later March than shown here. (Image credit: SkyandTelescope.com)

10 Mar.  Daylight savings time begins in most of North America at 2 a.m. today.  Say goodbye to an hour of sleep!

11 Mar.  New Moon, 19:51 UT.

17 Mar.  Jupiter makes a close encounter with a waxing crescent Moon in the constellation Taurus.  The bright orange star Aldebaran lies about 5º away from Jupiter for most of the month.  The Hyades and Pleiades star clusters round out tonight’s spectacle.  Jupiter is still a fine sight this month.  Its disc spans about 38″ and it shines at magnitude -2.1, far brighter than any star.  A fine sight in a small telescope.

Jupiter_March17

Jupiter, Alebaran, the Hyades, and the Pleiades (all upper left) as seen after sunset on March 17, 2013. Comet PANSTARRS lies just above the western horizon. Click to enlarge.

19 Mar.  First-Quarter Moon, 19:27 UT.

20 Mar.  Spring begins in the northern hemisphere and autumn begins in the southern hemisphere at 11:02 UT as the Sun crosses the celestial equator moving north.

27 Mar.  Full Moon, 9:27 UT.

31 Mar.  Daylight savings time begins for most of Europe  today.

Note: To find when DST begins and ends in your location, go to this link… http://www.timeanddate.com/time/dst/2013.html