After a journey full of surprises since it was discovered last year, fading and bursting back with a vivid tail, comet ISON surprised scientists and sky gazers alike one more time. In what was considered a final encounter with the sun, after ages of being drug by gravity from the outer reaches by our system's star, ISON showed itself once again after its grazing of the sun.
Considered a sun-grazer, the odds of ISON surviving it’s close flyby of 730,000 miles above the sun’s surface at 10 am(AK Time)were against it emerging from its sizzling ordeal, after much of its mass was broiled off into various gases. But emerge it did, although seeming much smaller and fainter than when it made its way on its final leg to our star.
Scientists worldwide watched as it approached, and at one point, dimmed considerably, then flared back to spectacular life as it may have begun to break up. Almost to a man it was determined that it would fizzle like a wet firecracker as the sun scarfed up its broken mass with its intense heat and gravity leaving only gas behind.
The dirty, 4.5 billion-year-old snowball of ice and rocks began its journey to the center of our system from the OOrt Cloud in the outer reaches beyond Pluto. Possibly nudged closer into our center by a passing star, ISON began its journey of 50,000 Astronomical Units(Astronomical unit, or AU is the distance from earth to the sun) as much one million years ago.
ISON would remain unknown to earth until September 21, 2012 when its existence was discovered by Russian astronomers Vitali Nevski and Artyom Novichonok using the International Scientific Optical Network reflector. Promptly named Comet Nevski-Novichonok, it soon would become known as ISON, the initials of the optical network that it was first observed with.(Lesser known is the comet’s designation of C/2012 S1)
It is thought that a part of the comet’s icy nucleus survived its close call with the sun. But, it may be just debris that survived the fly-by. “It certainly appears as if there is an object there that is emitting material,” said Alan Fitzsimmons, an astronomer with Belfast, Ireland’s Queens University.
It is unknown how long the comet will continue emitting gases, it will take a few days of observing it to determine if the tail will be sustained long enough to be observed with the naked eye from earth. “It now looks like some chunk of ISON’s nucleus has indeed made it through the solar corona, and re-emerged,” Karl Battams of the Naval Research Laboratory said. “It’s throwing off dust and (probably) gas, but we don’t know how long it can sustain that.”