Phil Plait is an astronomer, author, and science advocate. His blog, Bad Astronomy, is hosted by Discover Magazine, and he writes about news and current issues facing science. A common topic is astronomical doomsday: ways mythical and real the world can end. He's fascinated by asteroid and comet impacts, and is a big supporter of finding, tracking, and ultimately deflecting any dangerous rocks heading our way.

About TEDx, x = independently organized event

In the spirit of ideas worth spreading, TEDx is a program of local, selforganized events that bring people together to share a TEDlike experience. At a TEDx event, TEDTalks video and live speakers combine to spark deep discussion and connection in a small group. These local, selforganized events are branded TEDx, where x = independently organized TED event. The TED Conference provides general guidance for the TEDx program, but individual TEDx events are selforganized.* (*Subject to certain rules and regulations)