Ice in comets. Direct and indirect, massive amounts of evidence. But if you must have a photo. http://sci.esa.int/rosetta/59705-water-ice-in-imhotep-region/
2011 W3 was an unusual comet with very few volatiles, it only brightened when it got close to the sun. Similiar comets C/2012 E2 and C/2012 S1 in similiar sungrazing orbits appeared to be normal comets away from the sun and did not survive. I can pull up light curves for these comet's if you don't believe me. Btw how did you calculate your ablation rates?
No CO outgassing can drive activity out to 30AU
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Thank you for your input.
What I also find interesting is how they backtracked a photographic timeline from a 'dust plume' to find this in the same locale. Notice they say dust plume and not a vapor plume. Are they trying to say water is stripped off as 'dust'? In my post, I do not deny the presence of h2o in the coma and this small volume could be the product of an electrochemical reaction(for which all the conditions necessary are present) that eventually was stripped away. You keep saying there is massive amounts of evidence, of that I do not doubt, but there does not seem to be massive amounts of actual h20 or any significant amount that one would imagine should be required to support the 'dirty snowball' hypothesis. Considering the length of a comet tail, should there not be much more significant volumes of h20?
2.it is the unusual phenomena that bring cause to question. What kind of volatile can resist the extreme temperatures of the corona to produce a coma upon exiting the corona? That is the real question. The last couple of frames in the gif reveal a coma bursting forth ahead of the comet. Based on the fact that 'normal comets' do not survive such close encounters with the sun, I suspect not all comets are made of the same material suggesting that they are not all formed in the same manner.
In this graph published by Birkeland, he shows a correlation between sunspot activity and comet brightness. The lower curve represents the number of sunspots while the upper curve represents the brightness variations of comet Encke. This is highly indicative of an energetic relationship between the sun and comets. How does the dirty snowball hypothesis explain this?
Again I thank you for entertaining this conversation. It means a great deal to me to converse with someone who questions the model I favour for talking with other like minds feel like a group singalong rather than an intelligent critical conversation. My mind is open to opposing opinions, as well, it challenges me.
Water ice in comets: Infrared/Microwave spectroscopes on a number of the spacecraft sent to comets all show large amounts of CO2 and H2O in the vicinity of the nucleus. Look for results for the Microwave instrument aboard Rosetta, and the infrared spectrograph aboard EPOXI. Production rates of water byproducts like OH- have been monitored for decades in various parts of the spectrum (but you appear to be more interested in direct proof of a H2O parent, so for that we need to look at spacecraft observations).
Comet Encke and sunspots : I am a bit dubious of the graph and I'll tell you why (Birkland was brilliant, but not infallible). If that chart were the brightness of Comet Encke, it would show a very dramatic peak every 3.3 years coinciding with it's perihelion. During the 1800's Comet Encke was really only observed for a window of 2 months around perihelion, and any time outside it would be invisible. Since Birkland's time we have access to far more observations and more accurate observations and I haven't heard of any correlation. However, feel free to do your own data analysis, there is a good modern database of comet observations here. Keep in mind that comet brightness observations are notoriously difficult and there can be a lot of scatter, particularly between different observers.
Those readings in the vicinity of the nucleus could be the product of an electrochemical process which would be most active on the nose of the nucleus where solar wind(sheet current) is in greatest contact. Of the four comets that I am aware of that they have gotten close to there seems to be very little to no presence of water. The fact that there is this discrepancy between what we can see in the visual light range and what the sensors are reading suggest that there is something more to this. We agree that there is the presence of water, what we do not agree on is how that water is present. You insist on snow or ice, even though the images do not show any. Oh yes, it is subsurface, but even then from what I can ascertain, there was none observed by sensors or otherwise when they impacted a projectile and analyzed the ejecta. While I insist it is being produced via electrochemical process stripping atoms off the rock.
True enough about the brightness being difficult to measure and compare. Thanks for the link, I will check it out and given enough time may even link up a database on sunspots and graph the two together for comparison. A single comet clearly does not define all comets. But I do think Birkeland was on to something there.