Australian officials announced overnight that they have finished scanning the area where pings thought to be coming from missing Malaysia Airlines Flight 370 were detected, and no trace of the plane has been found. What's more, the U.S. Navy now says the pings they had based the search around probably didn't even come from the plane.

In a statement, the Joint Agency Coordination Center said in no uncertain terms that the months searching that particular swathe of the Indian Ocean had been fruitless. "No signs of aircraft debris have been found by the autonomous underwater vehicle since it joined the search effort," they said, adding

The Australian Transport Safety Bureau (ATSB) has advised that the search in the vicinity of the acoustic detections can now be considered complete and in its professional judgment, the area can now be discounted as the final resting place of MH370. 

A locater that search authorities had been using to pick up signals detected a number of pings within the specified area back in April. At the time, those signals were considered to be the strongest indicator of where the plane could be, though authorities warned that they weren't conclusive. But a U.S. Navy official told CNN last night that authorities believe the pings they were following did not come from the MH370's black boxes. If they had, the plane wreckage almost certainly would have been found by now.

After using an expensive Bluefin-21 robot submarine to cover an area measuring 330 square miles, authorities will have to start from scratch – in a much larger area, which could span up to about 37,282 square miles (located along an arc where a different ping was detected by satellite company Inmarsat.)

Speaking to parliament, Australian Deputy Prime Minister Warren Truss said that officials are, at least, still confident that the plane is in this ocean. Authorities will take some time to map the ocean floor in the newly expanded search zone before continuing to physically look for the plane sometime in August.