Comets bright enough to be seen without the aid of a telescope or binoculars are a rarity. This year may produce two such events. The first is now visible in the western sky after sunset, weather permitting. Comet PANSTARRS is actually Comet 2011 L4. Discovered in June 2011, comet 2011 L4 (PANSTARRS) bears the name of the telescopic survey that discovered it; "Panoramic Survey Telescope and Rapid Response System" which sits atop the Haleakala volcano in Hawaii.
The comet moved into the view of the Northern Hemisphere last week, but the best views should be over the next two weeks. You can follow continuing updates on the progress of the comet at Sky and Telescope. Viewing the comet may still be a challenge.
Comet C/2011 L4 PANSTARRS as seen from Mount Dale, Western Australia. The lights on the distant horizon are from the city of Armadale, which is southeast of Perth. Click on the image for a larger view. Image credit: Astronomy Education Services/Gingin Observatory.
"There is a catch to viewing comet PANSTARRS," said Amy Mainzerr, the principal investigator of NASA's NEOWISE mission at the Jet Propulsion Laboratory in Pasadena, California. "This one is not that bright and is going to be low on the western horizon, so you'll need a relatively unobstructed view to the southwest at twilight and, of course, some good comet-watching weather."
"Look too early and the sky will be too bright," said Rachel Stevenson, a NASA Postdoctoral Fellow at JPL. "Look too late, the comet will be too low and obstructed by the horizon. This comet has a relatively small window."
|This graphic shows the comet's expected positions in the sky. Click on the image for a larger view. Image credit: NASA.|
Any pair of binoculars will help in viewing the comet. The best view of the comet will be around March 12 in the Northern Hemisphere and it will gradually dim the remainder of the month.
The weather in South Carolina will provide near ideal conditions for March 12 through March 16. Skies will be clear enough for much of the week beginning on Tuesday after the frontal passage.
If you miss this event, there may be a better one later this year. Comet ISON is expected to pass about 800,000 miles from the Sun’s surface on November 28, 2013. If it survives the encounter, it could turn out to be the comet of the century. Comets are notoriously difficult to predict, so stay tuned.