Steven Halverson. Image http://www.reddit.com/r/interestingasfuck/comments/m57akt/this_is_my_clearest_picture_of_a_third_quarter/
Earths 5 extinction levels http://www.reddit.com/r/interestingasfuck/comments/m4iki1/earths_5_extinction_level_events/
Steven Halverson