Comet Pan-STARRS is one of the recently-discovered comets that will reach naked eye visibility in 2013. Brightness predictions for comets are notoriously unreliable, but Comet Pan-STARRS should be visible to the naked eye in the northern hemisphere from March 12, 2013 through the end of the month. Predictions suggest that this comet will be approximately as bright as the stars in the Big Dipper; and it has been visible in the southern hemisphere for a few weeks already.
Observing Comet Pan-STARRS
On its closest approach to Earth, Comet Pan-STARRS was visible from the southern hemisphere only. The comet’s closest approach to Earth, on March 5th, was about 100 million miles. During its closest approach to the Sun on March 10, Comet Pan-STARRS will be inside Mercury’s orbit. During this close encounter, tidal forces from the Sun might rip the comet apart. If the comet survives, the close encounter is likely to brighten the comet considerably, and give northern hemisphere observers a celestial treat.
The comet will become visible in the northern hemisphere, as soon as it moves far enough away from the Sun that the Sun’s glare does not overwhelm it.
According to NASA, for northern hemisphere observers, on March 12, Comet Pan-STARRS will be just south of the very thin crescent Moon just above the western horizon in the evening twilight. Each night thereafter, the comet will be a little further north and a little higher in the sky as it recedes from the Sun. As Comet Pan-STARRS moves higher in the sky, it will remain visible later in the evening. However, comets become fainter with shorter tails as they move further from the Sun. Depending on how bright Comet Pan-STARRS becomes, it will most likely fade from naked eye visibility by approximately the end of March.
To observe Comet Pan-STARRS, look for an observing location with a flat western horizon that is in a dark sky location. For a comet near the western horizon, observing locations west of a city are better than east of a city because the city’s light pollution will interfere less with seeing the comet’s diffuse tail.Decoded Science