Before his retirement after 2012, David Morrison, director of the SETI Institute, CSI Fellow and Senior Scientist at NASA's Astrobiology Institute at Ames Research Center, said he received 20 to 25 emails a week about the impending arrival of Nibiru: some frightened, others angry and naming him as part of the conspiracy to keep the truth of the impending apocalypse from the public, and still others asking whether or not they should kill themselves, their children or their pets. Half of these emails were from outside the U.S. "Planetary scientists are being driven to distraction by Nibiru," notes science writer Govert Schilling, "And it is not surprising; you devote so much time, energy and creativity to fascinating scientific research, and find yourself on the tracks of the most amazing and interesting things, and all the public at large is concerned about is some crackpot theory about clay tablets, god-astronauts and a planet that doesn't exist." In a similar vein, Professor Brian Cox Tweeted in 2012 that, "If anyone else asks me about 'Nibiru' the imaginary bullshit planet I will slap them around their irrational heads with Newton's "Principia"."