The Price of Silence — Deborah J. Ross

The crew of the spaceship Juno expected to find a fertile planet ready for colonization. Instead, they discovered a fiery grave and a space station filled with corpses. What had happened here? A natural disaster... or an alien weapon capable of destroying entire worlds? What were they willing to do, and what price were they willing to pay, to prevent another disaster?

Honorable Mention, Year's Best SF, 2009.
This story originally appeared in The Magazine of Fantasy & Science Fiction, April/May 2009