Hubble spots Comet ISON, comet on track to shine brighter than the moon

According to preliminary estimated made via the Hubble Space Telescope, Comet ISON is on track to provide the show of a lifetime as it passes by Earth and swings around the Sun in November and December.

LOS ANGELES, CA (Catholic Online) - The Hubble Space telescope captured a shot of Comet ISON when it passed just inside the orbit of Jupiter, about 386 million miles away from the Sun. The image reveals that Comet ISON is about 3-4 miles in diameter and is already outgassing vapor and dust at an amazing rate, consistent with a first-time visitor to the inner-solar system.

A comet making its first pass by the sun will have large quantities of material that are yet to be sublimated from its surface. This can make it brighter than a comet which has already made several passes by the Sun.

According to the data, the brightest part of the coma is about 3,000 miles across, roughly the size of the United States. The more diffuse material is spread across an area larger than Earth.

Comet ISON was spotted a year ago and quickly impressed scientists with its attributes. Quick calculations of its orbit revealed that it would pass every close to the Sun, which causes significant brightening in comets. If the comet survives its near-brush with our star, it will become exceptionally bright.

Astronomers think ISON could become brighter than the full moon, and will be visible in the daytime sky, making it a true "comet of the century."

Although comets are frequent visitors to the inner solar system, they are rarely visible to the naked eye on Earth. Less frequently, comets are so bright as to rival the moon. Such an event is truly a once-in-a-lifetime occurrence.

However, comets are infamous for their inability to conform to predictions. ISON could prove to be virtually invisible, it could break up around the sun, or it could put on a dazzling light show beyond all imaging.

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