Phil Plait, PhD, is an American astronomer and the brains behind the science blog “Bad Astronomy” and author of Bad Astronomy and Death from the Skies. He has been a part of the Hubble Space Telescope team, engaged in public outreach for NASA, and appeared in several documentaries including Phil Plait’s Bad Universe on Discovery. He has also in the last year joined the Youtube channel Crash Course where he hosts the astronomy unit.