Saturday Nov 30, 2013
19:42 UTC : Bye Bye ISON? A “sublimated” Comet is now reduced to a cone of molecules (mostly H and O) being blasted as a cone away from the sun by the solar winds. I wonder if the Northern Lights will be affected over the next day or two (estimated time for molecules to arrive at earth)?
00:19 UTC : ISON particles (after fragmentation) significant enough to track. Light reflects mostly from Oxygen. Usually tail points away from SUN towards future trajectory. Not in ISON’s case. Although not having a 3D image, it is hard to get a sense of the direction of the ISON sublimation blast cone. You can see here how the blast cone is unsymmetrical. To the left the particles are blasted out and away from the sun,but to the right the blast cone seems to be “pulled back towards the sun” by the turbulance.
Friday Nov 29, 2013 : Yesterday lunchtime at Cattle Point Urban Star Park, we bit our nails with excitement waiting for ISON to reappear from behind the sun (or SOHO’s sun cover). Google+/Youtube had carried the event live around the globe. It was an exciting build up. I was even pleased with Phil Tait’s involvement as the BadAstronomer.
As the critical moment came, and as we waited and waited, ISON did not reappear. One of the panel stated he was sure ISON had disintegrated (or sublimed), and a look of disappointment came across all the faces of the show participants as each came to the conclusion he was likely right. One by one with their tails beneath their legs, all the Google+ participants left the show. By 1 pm the show was over and ISON was DEAD.
NASA, keen to get home to their turkey dinners, sadly and quickly announced that ISON had “sublimated” with all its molecules absorbed by the sun’s heat and gravity. I was thinking that maybe the solar wind would in fact blast the particles below a certain size out in a cone which might or might not reach the earth in 2 days time – and that might still happen on Saturday.
Well with Google/NASA on their way to dinner, the only people left was ESA (European Space Agency). About 13:30 a twitter from ESA announced “Stay tuned, but it does seem that a remnant of ISON’s tail follows the comet’s trajectory. Images refresh here: http://soho.esac.esa.int/data/realtime/c2/1024/latest.html …
I couldn’t contain my excitement.
I twitter back to ESA :
@esascience the tail should point away from the SUN after the perihelion – so says all the blogs? True?
I quickly updated my Facebook to delete my new ISON is ALIVE post.
The evening and night passed slowly as I mulled over ISON’s demise. I was heartened by all the great science results people like Dr. Tony Remijan (ALMA) must have got and thought about Dr. Mike Mumma’s planned experiments which I expect will have produced many scientific advances ( see http://bcmeteors.net/index.php/77-news/170-ison-experiments-cioc ) BUT will ALMA finally prove that the seeds of life itself are carried by the (already proven) water of the core of ISON. Hopefully.
Well suddenly at 09:45 Friday Nov 29, we get the great news in an @ScienceChannel twitter that ISON (at least the tails and fragmented core) may have survived its trip around the sun : Science Channel
@ScienceChannel Comet ISON may have survived its trip around the sun! Here’s the latest: http://ow.ly/riFpU
What a roller coaster you are ISON. And “what next?” we are all asking 🙂
Predictions (in fun) :
- Great Northern Lights tomorrow + some satellite and radio issues starting tomorrow (as particles carried by solar wind reach earth)
- Great views of comet ISON starting in 2-3 days as the remnants shoot off to the Oort Cloud and possibly to another star. Early morning (6:30 am) in ESE.
- Exciting meteor showers mid-January (as earth passes close to the tail-end of the still surviving tail
Apparently Oxygen is the key element which gives bright light from a comet. So the trailing tail could be oxygen or even actually water vapour.
Question : Strange. The 2 tails are meant to point away from the sun after the perihelion. What are we seeing here? Could it be sunlight reflecting off the debris trail? Clearly a debris train containing much oxygen. So is it possible if ISON had not had this sublimation event that the tails would point in the opposite direction away from the Sun? But bright light means oxygen. So has disintegration caused trailing particles containing oxygen. My bet is this is mostly water (ie big particles), as if it was oxygen molecules the solar wind would have blasted the molecules AHEAD of ISON by now. Interesting. I await NASA/CIOC explanation.
I believe this image might show that the trailing 2 tails of ION’s and Dust, are replaced by a “cone” of particles being blasted out and away from the point of disintegration. Could this be what we are seeing? i.e. what leaves the “black circle” is quite different from what entered.