Scientists eye large, newly discovered comet that might crash into the sun in 20

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September 25, 2012 – SPACE - Astronomy forums are buzzing with speculation about newly-discovered Comet C/2012 S1 (ISON). Currently located beyond the orbit of Jupiter, Comet ISON is heading for a very close encounter with the sun next year. In Nov. 2013, it will pass less than 0.012 AU (1.8 million km) from the solar surface. The fierce heating it experiences then could turn the comet into a bright naked-eye object. Much about this comet–and its ultimate fate–remains unknown. “At this stage we’re just throwing darts at the board,” says Karl Battams of the NASA-supported Sungrazer Comet Project, who lays out two possibilities: “In the best case, the comet is big, bright, and skirts the sun next November. It would be extremely bright — negative magnitudes maybe — and naked-eye visible for observers in the Northern Hemisphere for at least a couple of months. Alternately, comets can and often do fizzle out! Comet Elenin springs to mind as a recent example, but there are more famous examples of comets that got the astronomy community seriously worked up, only to fizzle. This is quite possibly a ‘new’ comet coming in from the Oort cloud, meaning this could be its first-ever encounter with the Sun. If so, with all those icy volatiles intact and never having been truly stressed (thermally and gravitationally), the comet could well disrupt and dissipate weeks or months before reaching the sun.” Either of the above scenarios is possible, as is anything in between,” Battams says. “There’s no doubt that Comet ISON will be closely watched. Because the comet is so far away, however, our knowledge probably won’t develop much for at least a few more months.”  Meanwhile, noted comet researcher John Bortle has pointed out a curious similarity between the orbit of Comet ISON and that of the Great Comet of 1680. “Purely as speculation,” he says, “perhaps the two bodies could have been one a few revolutions ago.” –Space Weather

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October 2, 2012 – SPACE - If astronomers’ early predictions hold true, the holidays next year may hold a glowing gift for stargazers—a super bright comet, just discovered streaking near Saturn. Even with powerful telescopes, comet 2012 S1 (ISON) is now just a faint glow in the constellation Cancer. But the ball of ice and rocks might become visible to the naked eye for a few months in late 2013 and early 2014—perhaps outshining the moon, astronomers say. The comet is already remarkably bright, given how far it is from the sun, astronomer Raminder Singh Samra said. What’s more, 2012 S1 seems to be following the path of the Great Comet of 1680, considered one of the most spectacular ever seen from Earth. “If it lives up to expectations, this comet may be one of the brightest in history,” said Samra, of the H.R. MacMillan Space Centre in Vancouver, Canada. So what makes a comet a showstopper? A lot depends on how much gas and dust is blasted off the central core of ice and rocks. The bigger the resulting cloud and tail, the more reflective the body may be. Because 2012 S1 appears to be fairly large—possibly approaching two miles (three kilometers) wide—and will fly very close to the sun, astronomers have calculated that the comet may shine brighter, though not bigger, than the full moon in the evening sky. First spotted late last week by Russian astronomers Artyom Novichonok and Vitali Nevski of the International Scientific Optical Network (ISON), comet 2012 S1 was confirmed by the International Astronomical Union on Monday. But while we know what 2012 S1 is, it’s still unclear where it came from. Its orbit suggests the comet may be a runaway from the Oort cloud, where billions of comets orbit about a hundred thousand times farther from the sun than Earth is. Right now, 2012 S1 appears to be about 615 million miles (990 million kilometers) from Earth, between the orbits of Saturn and Jupiter, astronomers say. As the sun’s gravity pulls the comet closer, it should pass about 6.2 million miles (10 million kilometers) from Mars—possibly a unique photo opportunity for NASA’s new Curiosity rover. Current orbital predictions indicate the comet will look brightest to us in the weeks just after its closest approach to the sun, on November 28, 2013—if 2012 S1 survives the experience. As the comet comes within about 1.2 million miles (2 million kilometers) of the sun, the star’s intense heat and gravity could cause the ice and rubble to break apart, scotching the sky show.  “While some predictions suggest it may become as bright as the full moon and even visible during the day, one should be cautious when predicting how exciting a comet may get,” Samra said. “Some comets have been notorious for creating a buzz but failing to put on a dazzling display,” he said. “Only time will tell.”        -National Geographic

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December 30, 2012 – SPACE - A recently discovered comet that is rapidly approaching the Sun could outshine the Moon in 2013, researchers think. The comet may even be visible in daylight, as the Great Comet of 1680 was. It’s expected to be visible towards the end of the year, roughly from October to the following January. “The recently discovered object, known as comet ISON, is due to fly within 1.2 million miles (1.9 million km) from the center of the Sun on Nov. 28, 2013 said astronomer Donald Yeomans, head of NASA’s Near Earth Object Program at the Jet Propulsion Laboratory in Pasadena, Calif. As the comet approaches, heat from the Sun will vaporize ices in its body, creating what could be a spectacular tail that is visible in Earth’s night sky without telescopes or even binoculars from about October 2013 through January 2014.” With such a bright object in the night sky during the latter part of the year, it may somewhat drown out what will otherwise be a spectacular year of meteor showers in 2013. The comet will need to survive its approach to the Sun though, for that to happen. And it’s possible that the comet could disintegrate as it gets close to the Sun. Interestingly, comet ISON is following a very similar path to the famous comet of 1680, which was bright enough to be visible in the middle of the day. It is following such a similar orbit that researchers theorize that they may both originate from the same fragmented parent body. “Comet ISON could be the brightest comet seen in many generations – brighter even than the full moon,” wrote British astronomer David Whitehouse. “In 2013, Earth has two shots at a comet show. Comet Pan-STARRS is due to pass by the planet in March, eight months before ISON’s arrival. The last comet to dazzle Earth’s night-time skies was Comet Hale-Bopp, which visited in 1997. Comet 17P/Holmes made a brief appearance in 2007.” –Planet Save (excerpt)