A Dirty Snowball in the Sky
Comet C/2011, also known as Comet Pan-Starr, is now visible to the naked eye just after sunset in the western sky. This non-periodic comet was discovered in June, 2011 by the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS), an array of astronomical imaging devices and telescopes which survey the sky continuously.
The primary mission of the system is to detect near-Earth astronomical objects which might be considered impact threats to the earth. Located on Mount Haleakala on the island of Maui in Hawaii, the location allows the system to cover almost three quarters of the entire sky.
Comets are generally named after the observer who discovers the object and since the system detected the comet it has the name, Comet Pan-Starrs or Comet C/2011 L4. The designation of C/2011 L4 indicates it is a non-periodic comet (C), discovered in the first half of June (L) and was the 4th comet sighted during that time frame.
To see the comet look west just after sunset and about a fist high from the horizon. Binoculars will help you see the comet until it sets below the horizon. In California the best time to start looking for the comet is around 7:45 pm, DST.
The next big comet show will be in November through December when Comet ISON, discovered in Russia by the International Scientific Optical Network (ISON) telescope, appears in the winter sky. This comet is reported to be the brightest comet to cross the sky and may rival Halleys Comet.
Dirty Snowball? Comets are often referred to as dirty snow balls because the nucleus or head of the comet is nothing more than a clump of ice, rock and cosmic matter clumped together and illuminated by the sun’s solar wind. The term was coined by Astronomer Fred Whipple in 1950.