They really aren't pretty but they are amazing - the four pics of Comet ISON obtained by NASA's Mars Reconnaissance Orbiter (MRO) HIRISE camera. The pics were taken on September 29 at a distance of 8 million miles and more were planned for October 1 and 2 when the Comet was at 8 million miles.
You have to remember that these images were obtained from Martian orbit using a moving spacecraft's high powered telescopic lens that was designed to take images pointing down and covering a large area. To even capture Comet ISON in any manner is a technological victory.
The images were posted on the University of Arizona's HIRISE website - these are not from NASA so go here to read more about it: http://www.uahirise.org/releases/ison.php
We'll see what a million miles difference looks like when the other images are released.
Sky Guy in VA