[KarlInOhio]

http://cfa-www.harvard.edu/iau/Ephemerides/Comets/Soft00Cmt.txt gives the abolute magnitude as 10.0. Looking that up in http://cfa-www.harvard.edu/iau/lists/Sizes.html for an icy body (albedo = 0.5) gives a diameter of 19 kilometers. Lots of assumptions and uncertainty are in that estimate, but it at least will give you a general idea.

[Orlando]

Thank You