David Grinspoon is a prize winning author and gifted science communicator. He was the first Baruch S. Blumberg NASA/Library of Congress Chair of Astrobiology. His new book, "Earth in Human Hands: Shaping our Planet’s Future," is a look at how we as a species have been shaping the evolution of our planet and where that may be headed in the future. He also won the Carl Sagan Medal for Science Communication – which is pretty appropriate and cool as you are about to find out on this episode of Blue Dot.