Comet ISON should survive Sun encounter
The odds are pretty good that Comet ISON will survive its much-anticipated close solar approach next month, a new study suggests.
As long as ISON is a fairly typical comet — one with “normal” size, density and rotational characteristics — it probably won’t disintegrate during its upcoming flyby, which will bring the icy wanderer within just 730,000 miles (1.2 million kilometers) of the sun’s surface on Nov. 28, researchers report.
That’s good news for skywatchers, for Comet ISON could potentially put on a dazzling show if it manages to weather its solar encounter. And it’s also good news for scientists, who have been planning their most intense observations of the comet for after the flyby (since ISON will be easier to see from Earth after the approach than before).
In the new study, Matthew Knight of the Lowell Observatory in Flagstaff, Ariz., and Kevin Walsh of the Southwest Research Institute in San Antonio conducted simulations of Comet ISON’s upcoming solar approach, then put the results in context by looking at how other “sungrazing” comets have performed during their encounters with our star.
The possible outcomes for Comet ISON are total disintegration; initial survival with a breakup coming later, perhaps days or weeks after the Nov. 28 flyby; and full survival for another orbit around the sun. Which one of these will actually occur depends on ISON’s size and density, as well as the nature of its rotation (how fast it’s spinning, and in which direction), researchers said.
Comets less than about 0.12 miles wide (0.2 kilometers) face destruction by the sun’s heat, which can evaporate off all of their ices. But scientists think ISON is big enough to deal with this issue; most estimates place the comet’s core between 0.12 miles and 1.2 miles across (0.2 to 2 km).
here she comes..