The chaos cloud is a hoax that originated in a Weekly World News article in September 2005. It was published online at Yahoo! Entertainment News. According to the article, the chaos cloud is a massive object in outer space that "dissolves everything in its path, including comets, asteroids, planets and entire stars", and is due to reach Earth in 2014.
The hoax article generated a large amount of discussion online, as people attempted to discern whether or not it was genuine. Articles on the subject appeared at a diverse range of sites, such as Bad Astronomy, Whirlpool, Free Republic and Overclockers Australia. It has been debunked on Snopes and other urban legends sites.
References
Chaos cloud Wikipedia(Text) CC BY-SA