Small comets phenomena is amazing (I thought of it while reading the web feed from GreenieWatch-then to see another smart Freeper mention it-cool.) Anyways I read the book on the "snowball comets" in the early 1990s. More evidence of the 'divine design' of the universe and how God purposely planned a home for the crown of his creation - us.
"The Privileged Planet" is a very high quality documentary showing evidence that the Earth is uniquely suited for carbon-based life AND scientific discovery.
http://www.discovery.org/scripts/viewDB/index.php?command=view&id=2170&program=CSC%20-%20Video%20and%20Curriculum%20-%20Multimedia
That's just one more area of research that has been essentially smothered due to it's ability to demolish any "old earth" hypothesis. If it is real, then by the end of 100,000 years or so there would be five times as much water on earth as there is now.