The comet ISON may not be gone forever just yet. After coming too close to the Sun, the comet failed to show itself again and was almost entirely burned to a crisp in the Sun’s hot gaze.
NASA had been tracking the comet as it disappeared behind the Sun, knowing it could have been the comet of the century for Earthly viewers if it made it out the other side. But as it disappeared, the world waited with held breath to see if it would re-appear again.
In a live video from NASA, you can watch the comet approach the Sun and then disappear.
NASA last provided a public update on ISON at 2:15 in the afternoon, saying there was still hope it could re-emerge. But by 2:45, consensus seemed to grow that it was over and ISON was no more. Just after 3:00, NASA updated the world with the bad news.
But more than an hour later, some observers saw a hint of what might remain of the once-mountain-sized comet.
But a tail was all that remained. At 4:30, the European Space Agency confirmed that the comet was no more.
ISON was expected to pass just 1.2 million kilometres from the sun. In that range, the temperature can rise to more than 1 million degrees. At that range, the comet was thoroughly cooked. But it’s not the end of the world.
Had the comet survived intact and begun its trajectory away from the sun, sky watchers would have had a lot to look forward to in the coming weeks.
Paul Delaney, professor of physics and astronomy at Toronto’s York University, said ISON’s size and proximity to the sun could have ushered in a spectacular light show for those willing to wake up early and examine the pre-dawn skies.
You can watch NASA’s entire live chat about the comet and its approach here:
Comets are little more than vast chunks of rock that fall towards earth from the outer solar system. Delaney said that within the centre of those rock masses is a nucleus of volatile material that reacts to heat.
While several dozen comets travel near Earth every year, Delaney said many of them don’t come within close range of the sun. Those that do, he added, are often too small to become visible to the naked eye.
ISON appeared to be a different beast, he said, explaining that a comet becomes visible when the material contained in its nucleus becomes heated and begins emitting gas.
“The comet becomes surrounded by this sort of gas cloud, and this gas cloud can end up being literally tens of thousands of kilometres in diameter,” Delaney said in a telephone interview.
“It can trail material behind it for literally millions of kilometres, meaning that we’ve now got this object which has got a very large surface area to reflect light. And that’s what gives us a really terrific show here on Earth.”
ISON had a nucleus approximately two kilometres wide, making it comparatively large for one with such close proximity to the sun.
-with files from The Canadian Press