Space+or+Earth?

http://blogs.discovermagazine.com/badastronomy/2008/04/14/what-value-space-exploration/

Relative costs - go to the section 'So... What's the Real Story?'in http://www.astronomycafe.net/qadir/astravel.html Note the date.

Benefits of Space travel: http://www.thespaceplace.com/nasa/spinoffs.html

Space Exploration Benefits: http://www.buzzle.com/articles/space-exploration-benefits.html