Comet ISON – gone forever

What experts feared has finally happened: the nucleus of Comet ISON completely disintegrated during its passage near the surface of the Sun last November 28. At the same time, astronomers’ hopes of seeing a bright comet in the December sky were extinguished. Comet ISON has definitely kept astronomers watching with bated breath. In the hours before its perihelion passage, it was already showing signs of distress. The head of the comet, which had become brighter, started to weaken and stretch out as it left behind a significant trail of debris. At the same time, production of gas from the comet had almost ceased, indicating that all volatile components of the core had evaporated – presumably after fragmenting a few days earlier.

A glimmer of hope?

After its theatrical plunge into the solar hell, something quite bright seemed to exit on the other side! Could a large fragment of the core have survived after all? A few hours later this new hope was dashed as well, as the core residue dissipated. There’s nothing left but a cloud of debris traveling on the comet’s orbit, but that, too, will gradually disperse.

The Soho Satellite: understanding the trajectory of Comet ISON

The above image is a composite of photographs showing the evolution of the comet over four days, from November 27 to 30, 2013, around its passage near the Sun’s surface. They were captured by the SOHO satellite, which studies in particular solar flares and the solar wind. A device blocks the bright light of the sun’s surface, creating a kind of artificial eclipse so that the structure of the solar corona and even faint stars just a few degrees from our own star can be seen. The white circle in the center indicates the size and position of the sun. A full animation is available on the SOHO website. At present, the comet should already have been visible at dawn. Amateur astronomers have been at work over the last few nights, staring with telescopes and extremely sensitive cameras at the position where the comet ISON’s orbit should have been. In their images, not the slightest blur appears. The verdict is clear: nothing of significance remains of the comet. The famous Hubble telescope will also target this position over the next few days in search of the ghost of ISON, when it will have moved well away from the Sun. Still, experts are happy to have been able to observe the comet ISON in its death dive. They’ve accumulated massive amounts of data, which they will analyze in the coming months. When is the next spectacular comet, in terms of visibility to the naked eye? Unfortunately, this is impossible to predict. It would have to be a new discovery, because no currently known comet has the potential to deliver us a show worthy of the great comets of history – except perhaps the famous Halley’s Comet, which will make its next visit...in 2061!

Read also:

• Has the bell tolled for Comet ISON?
• The December sky: Could comet ISON have survived?
• The November sky: What does comet ISON have in store for us?