Right now at the Discovery Channel Store, buy the When We Left Earth set and get 2 more DVDs free.

When We Left Earth is the 4-DVD set in honor of NASA’s 50th anniversary, covering all sorts of stuff Dad would probably love. The bonus DVDs are Planet Earth Pole to Pole and Sunrise Earth: America’s Greatest Sunrises. So it’s 6 DVDs in all, for $69.95 and free shipping.

Plus, it’s edumakational.