As the blog post explains, it's a "special test" that discourages exploration and discovery and with a bland "1997, dial-up sensibility. Mars - A Curious blend of sulphur and rust with a sparkling whiff of carbon dioxide.
Postscript from Gary: Google already owns many of the domains that they might need for outer space exploration. We already have Google Earth.We'd like to have Google Mars and Google Google, NASA sign `a very big deal' from the San Jose Mercury News...
For example, imagine you wanted to see all the pages from the MarsExploration web site run by the NASA's Jet Propulsion Laboratory. You can get rid of NASA pages by doing this:
marsexploration " -host:nasa.gov