Comet ISON is doing just fine!

There has been a lot of speculation brewing over the past few days that C/2012 S1 aka comet ISON may either have already fragmented and fizzled, or is about to do so at any moment. I'm not going to point directly to any sources that are making these claims as I don't think those articles deserve the web traffic. Instead, I'll let you judge for yourselves: does this look like a fizzled out comet?


Comet ISON is looking more beautiful than ever in this image taken at Arizona's Mount Lemmon Observatory by Adam Block on October 8, 2013. [Image Credit: Adam Block via spaceweather.com]

That gorgeous image was taken just a couple of days ago and to me (and my colleagues on the CIOC), it looks a lot like a healthy comet! So I think it's time I gave an update on exactly what ISON is doing right now, and what we might expect of its future behavior.

At time of writing, comet ISON is approximately 1.48AU (~221 million km, 138 million miles) from the Sun, and 1.90AU (~284 million km, 177 million miles) from Earth, and is traveling at 34.6km/s (~125,000 kph, ~77,000mph). It recently made its close approach to Mars, and now is cruising towards its extremely close brush with the Sun just 50 days from today. [Cool fact: at perihelion, ISON will be traveling at a whopping 377km/s, or over 800,000mph!]

We really do not know what comet ISON is going to do when it gets near the Sun, and we have been clear about this from the beginning. Its passage through the solar corona is going to expose it to some really pretty insane solar radiation bombardment that will begin to furiously boil its surface away. In addition to that, the gravitational tug of the Sun will pull and stretch the comet, testing its structural integrity to the absolute maximum. Either, or both, of these factors could lead to its demise at any point in the days surrounding perihelion.

However, the CIOC's Matthew Knight recently published a paper in which he outlines his reasons for why he thinks comet ISON has a pretty good chance of surviving its encounter. I have known and worked closely with Matthew for nearly ten years now, and if I had to lay money down on ISON's fate, it would definitely be on Matthew's side of the fence! Of course all of us within the CIOC have slightly differing opinions of how ISON will perform but one thing I think we all agree on is that ISON will at least reach perihelion in some appreciable form, and put on a really good show in the solar spacecraft (e.g. SOHO and STEREO). Since the CIOC was formed in early 2013, we have stated that our best guess for ISON's peak brightness at perihelion will be around mag -3 to -5. After all these months, all the rumors and speculation, and all the reports of fizzling and fragmenting... we still stand by that as our best guess.


Comet C/2012 S1 (ISON) as imaged by Nick Howes, Ernesto Guido and Martino Nicolini on October 8, 2013, remotely using the 2m Liverpool Telescope in La Palma. [Click for full image!]
That is all in the future though, and really is just our educated guess - the comet itself may well prove us wrong. But what we can say for certain, right now, is that comet ISON is doing just fine! It continues to behave like a fairly typical, if somewhat smaller-than-average, Oort Cloud comet. It has given no indication that it has fragmented and while such an event can never be ruled out, we see no evidence or hint that the comet is in any imminent danger of doing so. Any reports to the contrary are just speculation.

How can we be so sure? Because we can see the comet! Opposite is just one more recent example of an extremely high-quality image of ISON taken by Nick Howes, Ernesto Guido and Martino Nicolini as part of a series of daily imaging sequences they have been recording to help study the morphology (shape, size, etc) of comet ISON.

And they are not the only ones! Every day now we are seeing new and beautiful images of ISON appearing on the SpaceWeather.com Comet ISON Realtime Gallery from astronomers, both professional and amateur, from all around the world.

With this wealth of imaging data we can see that as of one day ago at least, comet ISON was happy, healthy and seemingly in one piece. If you don't believe us, go out and find your local amateur astronomy club or observatory and find out when they are planning on viewing ISON. Then you can literally see it with your own eyes!

Keep up-to-date on the latest ISON and sungrazing comet news via my @SungrazerComets Twitter feed. All opinions stated on there, and in my blog posts, are my own.