A refugee suggested that a Prothean sphere could be located somewhere on Gei Hinnom in the Hades Nexus. Locate the sphere and inform the man at the Citadel refugee camp.
Listen to the refugee in the Docks: Holding Area on the Citadel. He is located in the area surrounding Bay E28, or point #4 on the area map.
Scan the tiny, lone planet of Gei Hinnom from the Sheol sector in the Hades Nexus cluster. The Hades Nexus sector will be accessible on the galactic map after completing the Priority: Rannoch
After handing over the artifact, you will gain 5 Reputation, 15,000 credits and an update to the Alliance Engineering Corps War Asset.