Yes, Comet ISON (a.k.a. C/2012 S1) has died. It probably existed 4.5 billion years as a conglomerate of dust and frozen gases, spending most of its time in the Oort cloud, between our solar system and nearby stars. A chance gravitational jostling by another similar body must have altered its velocity in a way that brought it into the inner solar system, and amazingly close to the sun. That's where it became "unglued" by the sublimation of ice to vapor and commenced a dispersal of fragments and dust that spread apart, never to be together again. Within a couple weeks it probably became so faint that only a large telescope could detect any of it.

I was hoping the Discovery Channel interviewer would ask me "What do you think will be your lasting impression about Comet ISON?" And I'd answer "That many people hate hypocrisy and hype, especially when their government does it!" But the question never happened, because the interview was canceled, presumably because Comet ISON died and there wouldn't be a spectacular view of it in the morning sky to justify the TV Special.

So why would I have given the "hypocrisy and hype" answer? Because that's what most of my "thank you" e-mails stated (I'm not accusing NASA or STScI or CIOC of hypocrisy or hype, I'm just relaying reader comments). My web page has had 215,000 visits (14 million hits). At first I was puzzled by the interest level in my web site. I didn't understand why people championed an amateur being the first to "recover" Comet ISON after the June/July solar conjunction. Was it because I showed that it was fainter than NASA's CIOC had expected? Instead of being called a "killjoy" for re-branding the "Comet of the Century" to ordinary comet status, people wrote with an underlying message that "the government has misled us again." Another theme was "How come an amateur beat NASA in recovering the comet?" And as you all know, every society seems to have a minority of "weirdo's" who in this case claimed that the government was keeping a secret about the comet's malicious intent. (I admit to laughing at the person who lifted an image from my web page and declared that the jet feature was in fact a UFO flying in formation.) But the common thread to many of the e-mails urging me to continue my web page had to do with a desire to have a place for news and information that was unbiased and not hyped. Even some scientist colleagues of mine, from years ago, expressed appreciation to me for a place that was free of hype and could be trusted.

On the one hand I was glad that people recognized my reports as straight-forward and un-hyped. "Calling it the way you see it" isn't always the best policy when a person is employed. But I'm retired, so it never entered my mind to alter my unvarnished interpretations. On the other hand, I was disappointed that so many people distrusted NASA. I really don't blame the Russian astronomer who invented the term "Comet of the Century," but I question the aggressive public outreach by CIOC which seemed to legitimize the spectacular spectacle conjectures, which they should have known would be picked up and exaggerated by the media. I've given considerable thought to this, and I sent CIOC an e-mail suggesting ways that NASA might consider for improving a public relations shortcoming that they may not recognize they have (receipt of the e-mail has not yet been acknowledged).

Let's change subjects, and get back to the comet. Keep in mind that "I'm no comet expert!" Until July, when a fellow astronomy club member issued a challenge to be the first in the club to image the comet, I didn't know diddley about comets. From what I have read Comet ISON was unique at the outset in two respects: 1) it came from the Oort cloud, so was a pristine sample of the original solar system nebula out of which the Earth and all other planets formed, and 2) it would be a sun grazer, allowing a more detailed analysis of the comet's chemical makeup.

The initial estimate for the comet's size, made almost a year ago, was erroneously large, and this fed speculation that it would become naked eye visible, and possibly very bright. A large comet nucleus, such as 3 km diameter, would be more likely to survive a close encounter with the sun, but Comet ISON was more like 0.6 km in diameter (based on MRO HiRISE albedo). Jakub Cerny (Czech Republic) correctly recognized the situation before perihelion, when he circulated an analysis that relied upon the many brightenings and fadings as evidence that the comet was small. After each brightening there was too much speculation that the comet might, after all, put on a spectacular show for the general public. It's natural for the media to exaggerate such speculation. Joe Rao (long-time comet aficionado, TV weather forecaster) noted that those who knew the most about comets were wisely refraining from speculating about Comet ISON's future, which reminds me of the cliche: "Those who know don’t talk, and those who talk don’t know." Whenever the comet did something unpredicted, the talking experts would say "Comets are like cats, they have tails and do whatever they want," and the cautious predictions kept on coming.

It is probably true that astronomers who specialize in the study of comets will learn a lot about comets, and maybe even the original solar nebula, from the many observations of Comet ISON. I doubt that lay people will ever appreciate these insights. This raises the perennial question of whether taxpayer money is justified being spent on such things. The question isn't going away because NASA and NSF seem to be shifting their research focus to comets, asteroids and exoplanets, and the U.S. Congress will be asking for answers. I personally think that exoplanet research can be easily justified (for philosophical reasons), and I think that the study of comets and especially asteroids can be justified for practical reasons - because comet and asteroid debris hit Earth every day (meteors and fireballs), and a "near Earth object" (NEO), i.e., a tiny asteroid, could impact Earth with little warning.

I hope Comet ISON will be remembered more for what we learn from it during the next few years (yes, that's how long it will take for the science results to happen), and less for it's disappointment in being a "no show" for the general public. I will remember Comet ISON for both of these aspects; but in addition I will remember Comet ISON for the thousands of loyal viewers who checked my web site for updates  215,000 times.

May whatever is left of Comet ISON "rest in peace," drifting in space, forever.

Bruce L. Gary
Hereford, AZ; USA


"The skylark, however high it flies, however heavenly its song, has a mortal body from which the song arises, and an earthly home to which it may and must return." Erwin Edman, The Contemporary and His Soul (1931).

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WebMaster: B. Gary.  This site opened:  December 13, 2013