My father was not only a planetary scientist and a great popularizer of science, but he thought very deeply about the world. He was a scholar, he studied history. He taught a class in critical thinking, and he was very, very aware of the directions we might go.

Dad was a difference maker. He reached out to people. He took them by the awe and wonder we feel over the most important questions we can think to imagine. He pulled them away from blind faith, away from pseudoscience, toward a deeper, richer understanding of the universe.

Life in space is impossible,' we're warned, and amidst the hypnotic beauty of these heavens, we become painfully aware of what a hostile environment space is, how unforgiving, how unsympathetic to human desires.

Something my father dearly loved is the scientific method, and it's founded in this element of humility. The idea is that you pursue the truth wherever it goes; you need to evidence, and you can - you see if it's repeatable.