2003 EL61
the strangest known object in the Kuiper belt
http://www.gps.caltech.edu/~mbrown/2003EL61/
I'm going to need braces...
a "name" tag from the same page linked by NormsRevenge above:
http://www.gps.caltech.edu/~mbrown/2003EL61/#impact
"One of the interesting predictions of this hypothesis is that the debris from the collision, from which the satellites formed, should have been composed predominantly of ice, rather than rock. The satellites themselves, then, should be almost purely ice... While the odd characteristics of 2003 EL61 and its moons initially led us to the hypothesis of a giant impact, the smoking gun came when we found the other icy debris left over from the collision in orbits similar to 2003 EL61 itself... Most of the other Kuiper belt objects have much more complex surfaces that are difficult to understand, but 2003 EL61, its satellites, and these five new objects all appeared unique. While trying to understand why these we different it suddenly became glaringly obvious that all of these objects were on very similar orbits, and that if you traced those orbits back in time you would be able to connect them to a single location where they were once part of a larger body (this is an oversimplification, but gets the main point)."