But the URL that shows up as a link in a comment is truncated like this due to auto-link creation triggered by the http part.
http://science.nasa.gov/headlines/y2010 ... ?list80669
The standard search window goes for an exact match of the URL, or character string, you entered and won't find it because it's truncated in the posts.
So when searching for a URL, click on Advanced Search below the standard search window, then enter the URL in the "Search for Keywords" text box and select the option "Search for any terms". The other options don't really matter in this case so just go to the bottom of the page for the "search" button.
If you use the full URL you'll get something like this
Hint:Search found 183 matches: (http|science|nasa|gov|headlines|y2010|02feb|asteroidcollision|htm|list80669)
You can narrow down the results by eliminating the front end of the URL, which would be common to many links, when you enter it into the search window:
This should be the result:
Hope that helps.Search found 14 matches: (y2010|02feb|asteroidcollision|htm|list80669)