Editor's note: Buzz Aldrin, whose new book is "Magnificent Desolation," was one of the two American astronauts who were the first people to set foot on the moon. [cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2009/images/06/23/art.buzz.aldrin.moon.jpg caption="Buzz Aldrin walks on the moon in a photo taken by Neil Armstrong, his colleague on the 1969 mission. "] By Buzz Aldrin Special … Continue reading Commentary: Let's aim for Mars