An Introduction to Planetary Defense Antonis Lilis English April 29, 2007March 25, 2008 1 Minute A group of American aerospace engineers have written a book on how to defend the earth against alien invasion. A limited preview can be found here. [ref] Share this:TwitterFacebookEmailLike this:Like Loading... Published by Antonis Lilis View all posts by Antonis Lilis Published April 29, 2007March 25, 2008
