The headline sez Australia, but the event described is in Antarctica. :')
http://www.freerepublic.com/focus/f-news/1641966/posts?page=76#76
http://www.freerepublic.com/focus/f-news/1641966/posts?page=147#147
http://www.freerepublic.com/focus/f-news/1641966/posts?page=148#148
http://www.freerepublic.com/focus/f-news/1641966/posts?page=149#149
But the size of the comet is described as only twice as that that wiped out the dinos. In my article it was described as 4-5 times.