Omega is a book by Jack McDevitt

Jack McDevitt

Jack McDevitt is an American science fiction author whose novels frequently deal with attempts to make contact with alien races, and with archaeology or xenoarchaeology....

 that won the John W. Campbell Award, and was nominated for the Nebula Award

Nebula Award

The Nebula Award is given each year by the Science Fiction and Fantasy Writers of America , for the best science fiction/fantasy fiction published in the United States during the previous year...

in 2004.

The mystery surrounding the destructive "Omega Clouds" (which are introduced in The Engines of God) is left unexplored until Omega.

Plot summary

A world of strikingly humanoid beings is discovered to be in the path of an Omega cloud, which attack and destroy anything with a sharp corner. The beings' civilization is strikingly similar to the early Greeks. Hutch is part of an expedition to save them if possible, using a new discovery.