Comet ISON May Suffer from Slow Death by Sun on Thanksgiving Day
NASA predicts that the comet ISON will slowly die out after a close encounter with the Sun on Thanksgiving Day, November 28, 2013.
The comet has been a treat for all sky gazers so far; its illumination increased 10 times after an outburst on on Nov. 13 and 14. Various observatories all over the world have captured beautiful snaps of the comet of the century.
This celestial guest is traveling through the inner Solar System for the first time and the astronomers don't really know what next will happen to the comet. Astronomer Matthew Knight from the Lowell Observatory, a member of NASA's Comet ISON Observing Campaign, predicted three possibilities that the comet may go through.
"I've grouped the possible outcomes into three scenarios, discussed in chronological order," Knight stated in a news release.
"It is important to note that no matter what happens, now that ISON has made it inside Earth's orbit, any or all of these scenarios are scientifically exciting. We're going to learn a lot no matter what."
The first scenario he foretells is that the comet may disintegrate on its own before encountering the Sun on Thanksgiving Day. Less than one percent of comets have been observed to disintegrate for no specific reasons, Comet LINEAR (C/1999 S4), which died out in 2000, and Comet Elenin (C/2010 X1) which collapsed in 2011 are two examples Knight gives. Both these comets were destroyed after entering the ~0.8 AU region of the Sun and ISON is entering the same region of space.
According to the second scenario, if ISON withstands all the challenges for the next few weeks, it will eventually reach its equilibrium temperature after confronting the Sun, which is around 5,000 degrees Fahrenheit. The comet comprises of dust and ice, which will vaporize because of the high amount of heat it will experience. This vaporization would make ISON shed its mass and help it develop a tail.
There are also chances for the vaporized comet to get pulled towards the Sun due to gravity. A sungrazing comet called Lovejoy died in Dec. 2011 after entering about 100,000 miles from the Sun's surface. It formed an elongated tail of dust on disintegrating.
The third scenario is that the comet may survive after encountering the Sun and continue living with its stock of nuclear fuel. The comet is likely to leave a trail of dust near the Sun if it stays whole. This trail is likely to spread and enlighten the morning sky like Comet McNaught (C/2006 P1) did in 2007.
Knight said that the best possibility would be if the comet breaks a little, leaving behind some big pieces, which the astronomers could examine. He said that he was rooting for the third scenario.
"Regardless of what happens, we're going to be thrilled," he predicts. "Astronomers are getting the chance to study a unique comet traveling straight from 4.5 billion years of deep freeze into a near miss with the solar furnace using the largest array of telescopes in history."
"Hang on, because this ride is just getting started," he advises.