Rated 1 out of 5 stars

-You get a toolbar with some links to popular astronomy websites.
-You get another search tool.
-You can easily create your own Firefox bookmarks to the same websites.
-You don't need another search tool.
-The toolbar inserts javascript code dynamically into your browser at runtime for all websites you visit. Inspection of the code is prevented so I can't tell you what it does. Use Firebug to reveal the inserted javascript load command. It is loaded from cloudfront.net in the 'head' section. Therefore this add-on...
-Possibly sacrifices your privacy