Casey Handmer has a PhD in Physics from Caltech and currently works at JPL (his views are his own), and he has one of the most engaged minds you will likely ever come across. He knows lots of things about lots of subjects. Just check out his blog ( https://caseyhandmer.wordpress.com/) to see for yourself. He was nice enough to stop by and chat about traveling, space, the universe, and lots more. He posts articles and analysis on timely and important space programs and missions.