Viewing Chart for Comet Panstarrs on March 12
Comet Panstarrs (C/2011 L4) was discovered in June 2011 by the Panoramic Survey Telescope and Rapid Response System (PannSTARRS) in Hawaii. Since then, the comet has slowly grown brighter as it approaches the inner Solar System.
The comet passes closest to Earth on March 05, 2013 (distance of 1.09 astronomical units) and it reaches perihelion (closest point to the Sun) 5 days later on March 10, 2013. It is during this period that Panstarrs is at its brightest.
The image above is a computer simulation depicting Comet Panstarrs' position in the sky about 40 minutes after sunset on the evening of March 12, 2013. Although the position of the comet can be predicted with great certainty, its brightness and the extent of its tail are only estimates. The simulation was performed for a location in the central United States (90° East longitude, 40° North latitude), but the appearance will be similar throughout the USA.
For much more information, see Comet Panstarrs or Bust.