Even though most of us were born into a solar system with nine planets, we now live in a solar system of eight thanks to the work of Mike Brown five-and-a-half years ago. His discovery led to an international body of astronomers demoting Pluto from a planet to a new category of dwarf planet.
Brown is a professor of planetary astronomy at California Institute of Technology. In 2005, his discovery of a world he initially named Xena was first thought to be the tenth planet.
Brown gave a lecture April 12 at the University of Minnesota. He spoke with The Daily Circuit while he was in town about his thoughts on how Pluto's demotion contributes to today's work in the astronomy field.
He discovered what could've been the tenth planet, but didn't support calling it a planet and then killed Pluto.
VIDEO: Michael Brown at THiNK 2011