Spanish author Juan José Benitez Wrote a "novel" where he talks about the asteroid named Gog which is due for impact on Earth in August 29, 2027 being of 15 km of diameter.

I had heard the date, had not paid much attention ("yet another apocalypse date to come and go") but today I came across the book at a friend's place and found it to be unnervingly detailed to be just another prank.