There is much speculation as to the size and makeup of comet ISON. ALL of the questions could be answered if NASA or any other agency with a radio telescope would just release their findings. Radio telescopes don't use visual imaging. It uses a type of radar and as such would be MUCH more accurate for answering the above questions. My question remains, where is the information? Where is the data?
Paul
Favorite Answer
Radio telescopes receive radio signals they're not radar stations. To get radar images of an object you need a radar station, but rest assured if it's possible to get an image of it, some astronomer somewhere will be bouncing radar signals over it. All it needs is a good clear look at it from a suitably equipped observatory.
Kudos for correctly naming C/2012 S1 (ISON) in the main question but remember don't call it comet ISON like too many other people are (and as I have been known to do), we need to break ourselves of this bad habit because this comet isn't named, no doubt the International Scientific Optical Network will be discovering more comets and it will get confusing if they are all called ISON. The bit in brackets isn't the name of the comet but the name of the observatory, if the comet does get named it will be called something like comet Nevski -Novichonok after its discoverers.
Lastly I just want to point out that NASA aren't the only astronomers in the world, there are loads of countries and loads of astronomers and observatories all over the place, NASA is just the American Space Agency not the governing body of astronomers. Also Americans seem to want to demand more and more from their space agency while paying them less and less. I think NASA's main goal with its tiny stipend these days is to get the James Webb Space Telescope built and launched.
Peter T
If you mean imaging using planetary radar from the Goldstone and Arecibo telescopes as has been done for many asteroids passing near the Earth then the plain and simple reason is that C/2012 S1 ISON is too far away at present. It is currently 400 million miles from Earth, between the orbits of Mars and Jupiter. Planetary radar experiments are only possible when an object is relatively near the Earth (of the order of about 10 million miles or less).
Some images taken by the Hubble Space Telescope have recently been released.
http://hubblesite.org/newscenter/archive/releases/2013/24/image/a/
John W
Radio telescopes do not use radar as it would take too long for the radio waves to reach another star and bounce off. You're not going to get a lot of data about a comet with a radio telescope. Besides, anyone with half a brain knows that comet will miss.
Jason T
Why do you assume they have any findings to release yet? Do you really think there would be speculation about it if that information was actually available from anywhere at all? NASA does not have a history of witholding data. If they had it it would be public by now.
I suggest you look up information on the limitations of radio astronomy, then see if your question is still valid.
digquickly
Well, ..., basically, C/2012 ISON is still to far away to be pinged by radar. So for now visual observations are all we can rely on. See Below.