Comet ISON fizzles as it rounds the Sun

Comet ISON - touted as the "comet of the century" - has fizzled out during its swing around the Sun, leaving behind a trail of dust rolling through space and disappointing stargazers.
Comet ISON went around the Sun yesterday. Several solar observatories watched the comet throughout this closest approach to the Sun, known as perihelion.
"While the fate of the comet is not yet established, it is likely that it did not survive the trip," NASA said.
The comet grew faint while within both the view of NASA's Solar Terrestrial Relations Observatory, and the joint European Space Agency and NASA's Solar and Heliospheric Observatory.

The comet was not visible at all in NASA's Solar Dynamics Observatory.
"We didn't see Comet ISON in SDO," said Dean Pesnell, project scientist for SDO.

"So we think it must have broken up and evaporated before it reached perihelion," said Pesnell.
While this means that Comet ISON will not be visible in the night sky in December, the wealth of observations gathered of the comet over the last year will provide great research opportunities for some time.
One important question will simply be to figure out why it is no longer visible, scientists said.
As Comet ISON headed towards its closest approach to the Sun - known as perihelion, scientists have been watching through many observatories to see if the comet had already broken up under the intense heat and gravitational forces of the Sun.

The comet was too far away to discern how many pieces it was in, so instead researchers carefully measured how bright it is, which is used to infer its current state.
Less light can sometimes mean that more of the material has boiled off and disappeared, perhaps pointing to a disintegrated comet.
At times observations had suggested ISON was getting dimmer and might already be in pieces. However, over November 26-27, the comet once again brightened.
In the early hours of November 27, the comet had appeared in the view of solar observatories.
If the comet has already broken up, it should disintegrate completely as it makes its slingshot around the Sun.

This would provide a great opportunity for scientists to see the insides of the comet, and better understand its composition - as such information holds clues about what material was present during the solar system's formation when this comet was born.