You'll probably be reading about this elsewhere soon, but I'm not aware of ay links currently to this story.
An asteroid, temproarily designated AT72198, was discovered late this afternoon. With 5 observations, the MPC (Minor Planet Centre) has calculated a preliminary orbt that brings it within 100,000 miles of the earth tomorrow. Collision has already been ruled out. I have not seen an estimate of size. It is moving quite fast, so the amateurs who usually follow up this sort of discovery have their hands full trying to re-find it.
Here's a copy of a post on the minor planet mailing list from a member of the MPC:
"Nice object... 5 positions, very bright. Good fit bringing
the object to about 0.0009 AU in 15+ hours from now. Will
be interesting to see how good this prediction is. I was
fairly careful with the uncertainty map. Impact is ruled out
(NOT OUT TO DINNER THIS TIME!"