Thursday,  March 14, 2013 • Vol. 14--No. 238 • 11 of 31 •  Other Editions

Moon still points to Comet Panstarrs west after sunset March 14

• After sunset on March 14, use the waxing crescent moon and binoculars to find Comet Panstarrs (C/2011 L4) near the western horizon. Find a level and unobstructed horizon in the direction of sunset, and note where the sun sets on the horizon. Then search for the

comet above the sunset point as dusk ebbs towards nightfall. Depending on viewing conditions, the comet should become visible through binoculars around 45 to 60 minutes after sunset.
• The lighted portion of the crescent points downward, toward the sunset point. It points in the direction of the comet on March 14 because, at this time, Comet Panstarrs is still rather close to the ecliptic (sun's path) on the sky's dome. In other words, you can use the lighted portion of the moon tonight like an arrow, pointing the way to PANSTARRS low in the western sky after sunset.
• Will the comet be obvious? No. But you can see it, even from cities, if you scan with binoculars. Draw an imaginary line on the sky's dome from the lighted portion of the moon, down to the sunset point on the horizon. Then start at the horizon and scan side to side, upwards along your imaginary line. The comet is much closer to the western horizon than the moon is. It's near the horizon in fact. So start at the horizon and scan side to side with your binoculars, upward along your imaginary line. You should see the comet.
• You'll have a much better chance of spotting Comet Panstarrs in the Northern Hemisphere. That's because at sunset in March, the ecliptic hits the horizon at the steepest angle for the year at northerly latitudes, but at its shallowest angle at southerly latitudes. Since the comet still resides fairly close to the ecliptic, it'll set later after sunset in the Northern Hemisphere.
• After today, Comet Panstarrs is expected to grow dimmer as it travels northward of the ecliptic. It is now in the constellation Pisces and heading for the far-northern

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