Ghost of Comet ISON Fading Fast

Fast fading Comet ISON (at upper right of frame) before it leaves view of SOHO satellite on Nov. 30. Credit: ESA/NASA/SOHO
Fast fading Comet ISON (at upper right of frame) before it leaves view of SOHO satellite on Nov. 30. THe white circle at center represents the sun’s position. Credit: ESA/NASA/SOHO

After initially appearing to revive after whipping around the sun on Thursday, Comet ISON has kept on providing space buffs with a real roller coaster ride. (Related: Comet ISON Barnstorms Sun)

But while hopes were raised that the comet might have been only been battered and bruised by its encounter with the sun, it now looks like it received a fatal blow. Only a headless dusty specter of the comet appears to remain.

Comet and solar scientists eagerly scanning images beamed back from NASA’s Solar Dynamics Observatory satellite on November 28th were disappointed to see that ISON seemed to go missing in action after the icy visitor passed within 683,000 miles (1.1 million kilometers) of the surface of the sun. This left  astronomers scratching their headsspeculation was that ISON’s frozen nucleus might have completely disintegrated as its vast reservoir of ice was evaporated by the intense solar heat.

Hours later however, to the surprise of the entire astronomical community, the stealthy comet appeared to resurface on wide-angle views from the space agency’s SOHO spacecraft, clearly showing that something had made the hairpin turn around the sun. The comet appeared to brighten and form a fan-shaped tail.

ISON appears as a white smear heading up and away from the sun. ISON was not visible during its closest approach to the sun, so many scientists thought it had disintegrated, but images like this one from the ESA/NASA Solar and Heliospheric Observatory suggest that a small nucleus may be intact. Credit: ESA/NASA/SOHO/GSFC
ISON appears as a white smear heading up and away from the sun. ISON was not visible during its closest approach to the sun, so many scientists thought it had disintegrated, but images like this one from the ESA/NASA Solar and Heliospheric Observatory suggested initially that a small nucleus may have remained intact. Credit: ESA/NASA/SOHO/GSFC

The day after the solar encounter there was a feeling of optimism.  With a distinct brightening observed, initially it looked like a zombie-form of Comet ISON may have partially survived its roasting. But as of late December 1st,  reports are now looking much more pessimistic, indicating that in all likelihood that the comet indeed did disintegrate, leaving behind only a ghost of comet ISON in the form of a dust cloud.  This theory appears to be bolstered by new satellite images which show it fading fast as it continues to recede from the sun.

This weakening trend obviously does not bode well for those hoping for a flashy sky show later this weekone that was initially predicted.

According to spaceweather.com’s website, ” Experienced astrophotographers might be able to capture the comet’s fading “ghost” in the pre-dawn sky, but a naked-eye spectacle is out of the question.”

The best chance for photographers and hopeful skywatchers with binoculars to capture views of Comet ISON”s remains will be in the pre-dawn skies of early December.

Illustration showing where to search for remain of Comet ISON in the east-southeast skies before dawn. Credit: NASA
Illustration showing where to search for remain of Comet ISON in the east-southeast skies before dawn. Credit: NASA

 

The comet can’t be laid to rest just yet, and many satellites, including the Hubble Space Telescope will be on the case, trying to view any remains of Comet ISON as it heads back towards the frigid recesses of the outer solar system that it came from some 3.5 billion years ago.

So hopefully we may still have a few nice, space-based, parting shots of this much hyped icy interloper to look forward to.

 

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Changing Planet

Andrew Fazekas, aka The Night Sky Guy, is a science writer, broadcaster, and lecturer who loves to share his passion for the wonders of the universe through all media. He is a regular contributor to National Geographic News and is the national cosmic correspondent for Canada’s Weather Network TV channel, space columnist for CBC Radio network, and a consultant for the Canadian Space Agency. As a member of the Royal Astronomical Society of Canada, Andrew has been observing the heavens from Montreal for over a quarter century and has never met a clear night sky he didn’t like.