Astroblog: Has Comet ISON disintedgrated? (or is it disintedgrating)

Tuesday, November 26, 2013

Has Comet ISON disintedgrated? (or is it disintedgrating)


Comet C/2012 S1 ISON in the medium resolution PNG images from H1A on 23 November. If you click the image you can see a bright "knot" in the tail.	Comet C/2012 S1 ISON in the medium resolution PNG images from H1A on 25 November. The comet still apears to be healthy, but looks can be decieveing

There has been a lot of buzz in the astronomy community over the last 8 hours of so over news that comet C/2012 S1 ISON may be breaking up/ has already broken up. There are several elements to this.

A CalTech team using the IRAM millimeter telescope in Spain has reported a 20 fold fall in molecular emission lines from 21 November to 25 November. They interpret this as a disintegration of the comet. The TRAPPIST team reports a fall in dust production rates by a factor of 3, AfRho measurements by the CARA team suggest nuclear erosion. Terry Lovejoy has measured strong non-gravitational forces which may suggest a breakup. Dan Fishers notes an alternate view of the CalTech results.

Against this the comet looks healthy and brightening in the STEREO images. This could be due to the comet being an expanding cloud of reflective dust though.

Labels: C/2012 S1 ISON, Stereo Satellite

# posted by Ian Musgrave @ 8:30 am

Comments:

Your comments seem rather odd given that the stereo A camera shows a healthy and HUGE comet !!
BPEarthWatch.com (latest) Makes good sense to me. Too much subjective media blogs are happening at this time. If Nasa has been withholding radio images for such a long time, what is this saying ? Coverup of something BIG is happening. Jessie has the comet at 18,000 miles diameter.

# posted by

Anonymous : 12:07 pm

No, the H1A camera has the resolution of a good pair of binoculars, it cannot determine, at this stage, where we are seeing a healthy comet OR a mass of expanding dust from a disintegrating comet.

What you are sing in the H1A images is not the cometary nucleus, but the atmosphere of dust and gas around the nucleus, the coma. The nucleus is at most 5 km in diameter, but the coma is much larger.

NASA hasn't been withholding any radio images, the radio telescope data come from completely independent astronomers (and are not images, but radio spectra).

All the amateur images and measurements (and there has been lots of serious activity over the past months), give results of a smallish comet, gas rich and dust poor.

The H1A images show the comet growing slowly in brightness, but with the resolution of the H1A camera, we can't say if the nucleus is intact for a few more days (although the latest beacon image suggests it is staying intact)

# posted by

Ian Musgrave : 12:20 pm

I would say first off I'm no scientist by any means first. To me both pictures of comet Ison in the H1A seem still promising. The reasoning I have by saying this is because in the 2nd image Ison's center nucleus seems brighter. This H1A camera does not have the resolution needed to see what is around that nucleus. My thinking is that as Ison gets closer to the Sun that it will continue to brighten in the spectrum because of the intensified heat of the Sun caused from a closer distance to the Sun. Also, I would further say that it should be getting brighter due to the fact that the Sun's gravitational force should be pulling on Ison more and more as it gets closer. That would cause Comet Ison to get hotter and hotter as it is well beyond speeds that the mind can grasp. At a molecular level the heat would be so intense mixed with gravitational tugs that it should brighten; such as the pictures of H1A are showing. Unless a better resolution is seen you can't make an assumption of it breaking up. Also, lets be honest here....we have no idea exactly what Comet Ison is made of. Most scientists say they are dirty snowballs of ice and dust. I'm sure some comets are, but others may be made up of other worldly chemistry off the periodic charts. What if Ison was a planet such as ours that got hit by a huge asteroid that knocked it out of its orbital path? If such a thing happened to Earth and it was hurtling through space for 580,666years(as NASA new data says) then all of earth oceans and land masses would surly fly off, and it would eventually only leave the core which is made up of Iron. What would happen to Iron at those speeds and under that kind of intense heat and gravitational tugging? My guess is that it would become brighter and brighter. The fact is that we all don't have enough information to exactly know really that all comets are dust and ice to form an exact opinion of what any comet will do. That's my point that I'm trying to get at. Jumping to conclusions is not what true scientists do. All they can to is calculate based off speculation! Lets just watch and observe.
Robbie B.

# posted by

Unknown : 9:43 pm

Hi, whats the mini comet shown just below comet ISON on the second picture, and just above it on the first picture ?
Can anyone else see it in the picture ?

# posted by

Astro Phil : 10:47 pm

That is 2P Enke

# posted by

Ian Musgrave : 11:18 pm

Will this be seen in SE Australia? I'm on your blog because we ss the most amazing comet last night with the longest tail.
BW

# posted by

Anonymous : 9:59 am

G'Day BW

No, it will not be seen in Australia at all, see the posts here http://astroblogger.blogspot.com.au/search/label/C%2F2012%20S1%20ISON

What you saw was probably a meteor, there are no unaided eye comets around at the moment.

# posted by

Ian Musgrave : 10:04 am