People searching for missing Malaysian Flight 370 found new clues and hope Wednesday.
An Australian navy vessel picked up two more underwater ping signals in the southern Indian Ocean.
The Australian ship, also called "Ocean Shield," has detected four transmissions from the area.
Crews hope they're coming from the plane's data recorders, which are on their last leg of battery life.
Many have compared the search to trying to find a needle in a haystack.
"I believe we are searching in the right area, but we need to visually identify aircraft wreckage before we can confirm with certainty that this is the final resting place of Flight MH370," Chief Search Coordinator Angus Houston said.
Officials want to narrow the search area so they can deploy a small submarine or underwater vehicle to search for debris on the sea floor.