NASA's messenger at Mercury will be taking pictures of the flybys. But will they actually release any of them? I won't hold my breath since they haven't released any pictures of ISON so far.
from site: MESSENGER Detects Comets ISON and Encke, Prepares for Closer Encounters
NASA's Mercury-orbiting MESSENGER spacecraft has captured images of two comets -- 2P/Encke and C/2012 S1 (ISON) -- setting the stage for observations later this month when both comets will be substantially brighter and much closer to Mercury and the Sun. [more]
Here is Hubble's ISON page. Notice they mention things (ISON's outburst) - but not a single picture from them. Oh, notice how they say... ISON only as Hubble can see it. Yet.. no image!
The pictures NASA have of the two comets on their site is a joke! Give me a break, this is the best they can do? Here are the pictures they/NASA released of the comets.
Also take a look at the NASA site of their bigger pictures of both ISON and Encke. You will find they have amateur photographs of the comets. Not a single one from a telescope of theirs.
Funny considering we the public are the ones who support NASA, yet they hide everything from us.
Here is ISON's orbit from JPL
So what is it about ISON that NASA doesn't want to release up close pictures of it? They don't want to show themselves as lying all these years, saying that Comets are just big things of ice?
This guy found Hubble images of ISON from May.
One thing is for sure. I sincerely hope that amateur photographers/astronomers will be out tomorrow morning and the next getting pictures of Mercury as the comets interact with it.
Here is the best site (Earthsky.org) I have found for information about ISON and it passing by Mercury. There are pictures, etc. of where it will be in the sky.
I wish I had a really good telescope and camera to get pictures of it.
UPDATE 11/17/13 - 11:20 am EST - Upclose Picture of ISON Coma from Ison! Perfectly Round Coma with two additional objects in it.
