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Bright comet to come into view

Elizabeth Howell, News Writer
Feb 23, 2013, 8:00 UTC

Sen—Skywatchers in the northern hemisphere, prepare yourselves for a little treat. A bright comet is about to shine before your eyes, if projections come to pass.

Comet Pan-STARRS (more formally known as Comet C/2011 L4) is currently brightening in the southern hemisphere, and it will be visible as far north as Hawaii starting on March 7.

The icy ball of material is expected to reach a brightness of magnitude 2 or 3, which is easily visible with the unaided eye. 

Pan-STARRS is a visitor from the Oort Cloud, a collection of icy bodies believed to orbit the sun far beyond the position of Neptune. First proposed by astronomer Jan Oort in the 1950s, astronomers now believe that as many as 0.1 to 2 trillion ice-filled bodies occupy this space.

Every so often, a stray gravitational pull will send one of these denizens further into the solar system. The brightest can shine in Earth's sky for months. Past civilizations saw comets as heralds of doom or change - just ask William the Conquerer, who is said to have believed a comet in 1066 foretold his victory in England.

This is the first time Pan-STARRS will make the journey close to the Sun and Earth. Nobody yet knows how the increased gravity and sunlight will affect the comet. It could pull the comet apart prematurely, or alternatively, turn it into bright object easily visible to amateur astronomers.

"Prepare to be surprised. A new comet from the Oort Cloud is always an unknown quantity equally capable of spectacular displays or dismal failures," stated  Karl Battams of the United States' Naval Research Lab in a NASA press release earlier this month.

The best dates to observe Pan-STARRS will be March 12 and 13 at sunset, when the comet glistens near a crescent moon. That's providing the comet survives its closest approach to the sun on March 10.

Astronomers first spotted the comet in 2011 using the Panoramic Survey Telescope and Rapid Response System. The comet was named after the Hawaii observatory that found it.

Comets are considered a time machine that include ices and other materials that formed in the early solar system. Studying these bodies provide clues to how the solar system came to be.

Most comets are only occasional visitors to our solar system - sometimes only once, or sometimes once every few thousand years. One notable exception is Halley's Comet, which swings by Earth every 75-6 years or so. It's possible for a human to see it twice in his or her lifespan.

Skywatchers are also keeping their eyes peeled for another comet that could shine brightly in the daylight sky in late 2013, if it lives up to the most optimistic predictions.

Comet ISON is projected to appear as a bright naked-eye object in Earth's sky in November 2013. At its closest to the Sun, it will pass within 800,000 miles (1.2 million kilometres) of the surface.

Astronomers caution, however, that it is difficult to predict if the comet will survive the journey, and how spectacular the tail's eruption will be.