Ever since the comet was discovered by Russian astronomers night sky watchers all over the world have been hoping that ISON (which was named after the organization of its finders, the International Scientific Optical Network, and whose scientific name is the somewhat less fancy C/2012 S1) would be the next big thing in the night sky. Many observers have followed ISON’s path since its discovery in September 2012.
Comets are fickle creatures as far as publicity is concerned, and whenever there seems to be an exceptionally grand hype about a comet it appears to spite the news and turn out to be a complete loser in the spectacle department. Anyone remember comet Kohoutek? We had T-shirts, mugs, bumper stickers, the whole nine yards and then some. We were supposed to be able to watch it with the naked eye comfortably seated in a lawn chair in our own backyard … and then — nada. Kohoutek fizzled out as if all the excitement had scared the living daylights out of it.
Since then, astronomers have been far more cautious in stirring public excitement about a comet. And truthfully, the vast majority of comets are discovered by other spacecraft quite by accident — they observe the night sky or the sun according to their mission specifications, and then a stray comet will photobomb a series of observations.
During my last visit to Griffith Observatory in Los Angeles I watched a young actor-scientist create a comet replica out of dirt, water, rocks and liquid nitrogen, much to the delight of a packed audience. And indeed, the end result looked like a dirty snowball, and as the bright lights and warm ambient temperatures boiled off the frozen materials one could indeed see a comet’s tail as the self-proclaimed mad scientist waved it through the air with an appropriate maniacal cackle.
Comets are fascinating odd cousins in our solar system. Some of them, such as Halley’s comet, return for visits in predictable intervals over a period of hundreds of years. Some come and go and are never seen again — or their orbits are so eccentric and long that nobody recognizes the visitor from the last encounter. Some of them break up due to gravitational forces, such as the infamous Shoemaker-Levy fragments that plunged into Jupiter’s dense atmosphere.
Many of our annually occurring meteor showers are in fact debris fields left behind by comet tails, delighting us with “shooting stars” and lots of wishes.
As far as ISON is concerned, its orbit classifies it as one of those come-and-go guys that we’ll likely never see again. That alone makes it a bit of a mystery. ISON never quite attained the rock star status that astronomers hoped for — you needed a bit of optical help to even see it. The moment of its closest approach to the sun occurred on Thanksgiving Day, and even if it had brightened to naked-eye-visibility, as cold as it was here very few people would have braved the low temperatures to see something you can comfortably watch on your laptop just as well, holiday cheer in hand and belly overextended from eating way too much.
ISON disappeared from view when it skimmed the sun’s surface at less than a million miles away, and most everyone declared it dead. But comets are kind of like cats: they do exactly what they want. And so ISON re-appeared when hope was all but gone, brightening tremendously as it sped away from the sun and earning itself the nickname “Zombie Comet.”
Now, it may only be a tiny fragment of the nucleus that survived the fiery plunge, but it was clearly visible in the view of several solar observatories.
By the time you read this article ISON may be gone altogether. But at least we have some beautiful images of its visit to our neighborhood as well as some awesome videos.
And if nothing else, ISON reminded us how exciting life in this universe can be.
Check out NASA’s ISON website at http://solarsystem.nasa.gov/smallworlds/cometison.cfm
Beate Czogalla is the professor of theater design in the Department of Theatre and Dance at Georgia College & State University. She has had a lifelong interest in space exploration and has been a Solar System Ambassador for the Jet Propulsion Laboratory/ NASA for many years. She can be reached at firstname.lastname@example.org