Sounds like a great beginning for a 1950's Sci-Fi movie plot:
http://www.msnbc.msn.com/id/28023860/
Seriously, if it is from another star system, this would be worth
getting a sample return mission to.
So we sent out a probe to do a flyby of it... and as the probe
approached, we first saw written on the surface of the comet those words
of terror that could spell the doom of mankind: "Space Battleship Yamato
is destroyed...all your anime are belong to us." :-D