Post date: Nov 28, 2013 11:57:40 PM
Comet ISON vanishes as it moves around the Sun, possibly destroyed, according to scientists.
ANIMATION (NOVEMBER 28, 2013) (NASA TV) - A comet's 5.5-million-year journey to the inner solar system apparently ended during a suicidal trip around the sun, leaving no trace of its once-bright tail or even remnants of rock and dust, scientists said on Thursday (November 28).
The comet, known as ISON, was discovered last year when it was still far beyond Jupiter, raising the prospect of a spectacular naked-eye object by the time it graced Earth's skies in December.Comet ISON passed just 730,000 miles (1.2 million km) from the surface of the sun at 1:37 p.m. EST/1837 GMT on Thursday. Astronomers used a fleet of solar telescopes to look for the comet after its slingshot around the sun, but to no avail.
Scientists believe comet ISON appears to have flown too close to the sun and broken up in its corona. They had had hoped that the comet from the farthest reaches of the solar system would be able to slingshot around the sun Thursday and emerge streaming a tail visible to the naked eye next month. But after NASA telescopes tracked the comet plunging into the sun's corona, no evidence of it emerged on the other side.
"At this point, I do suspect that the comet has broken up and has died," astrophysicist Karl Battams, with the Naval Research Laboratory in Washington, said during a live broadcast on NASA TV. "But ISON has surprised us a lot over the past few months so let's at least give it a couple more hours before writing the obituary."
At closest approach, the comet was moving faster than 217 miles per second (350 km per second) through the sun's atmosphere.
At that distance, it reached temperatures of 5,000 degrees Fahrenheit (2,760 degrees Celsius) - hot enough to vaporize not just ices in the comet's body, but dust and rock as well.
If the comet or any large fragments survived the close encounter with the sun, they would be visible to the naked eye in Earth's skies in a week or two.
The comet was discovered last year by two amateur astronomers using Russia's International Scientific Optical Network, or ISON.
Comets are believed to be frozen remains left over from the formation of the solar system some 4.5 billion years ago.
The family of comets that ISON belongs to resides in the Oort Cloud, located about 10,000 times farther away from the sun than Earth, halfway to the next star.
Occasionally, an Oort Cloud comet is gravitationally nudged out of the cloud by a passing star and into a flight path that millions of years later brings it into the inner solar system. Computer models show ISON was a first-time visitor.