Since imaging comet C/2012 S1 ISON at the Deep South Regional Star Gaze (DSRSG), see my previous post, I have been fascinated by this visitor from the outer reaches of our solar system - presumably the Oort cloud. {The Oort cloud is thought to be roughly a light year away and is considered to be source of many of the comets we observe in the inner solar system.} According to a NASA website, around one million years ago, a rather unremarkable cloud resident was ejected and gravitational forces destined it to a perilous journey to the inner solar system and a close encounter with the sun.
Fast forward to Sept 2012 when Russian astronomers, Vitali Nevski and Artyom Novichonok, discovered the small,bright object when it was some 585 million miles distant, just beyond the planet Jupiter. Detailed measurements of it's trajectory revealed the comet's rendezvous with the sun would be a very close one. If it survived ISON would likely put on a brilliant post-perihelion display in December of 2013. However the relatively small size of the comet ( 3-4 miles in diameter) and the closeness of its approach to the sun make its survival a IF.
There has been much speculation in the astronomical community and some have dubbed ISON to be the "comet of the century". The wide spread use of social media have enabled astronomers to reach millions with ISON's story and the public news media has been a buzz about the potential for a spectacular show. Such public outreach is vitally important to astronomy and science in general as it offers the potential to inspire the next generation of would-be scientists. A bright comet appearing in the night sky, and possibly even during daytime, could make an indelible imprint on many young minds that could lead them to study science and eventually a scientific career. Conversely, if the much hyped event turns out to be a dud, we could loose this opportunity.
Since ISON's sun grazing on Thanksgiving day, astronomers have been anxiously watching to learn the comet's fate. Early reports were that it had disintegrated upon approach to the sun. Then came reports of survival, albeit badly wounded, with intriguing pictures of a fan-shaped trail emerging from the sun's glare. This morning the reports are that the object is rapidly fading, suggest that ISON may be no more that a debris field scattered by the solar wind. The final ISON images as it passes away from the SOHO cameras show ISON's demise. The final analysis will have to wait a few more days. Possibly later this week ISON's remnants will be visible in the predawn skies low in the east-southeast, but it is unlikely to be visible to the naked eye. Weather permitting, I'm planning to try for one last image this coming weekend.
