Australian Prime Minister reiterates 'high degree of confidence' in finding MH370

"No one should underestimate the task ahead of us," Prime Minister Abbott said. "Trying to locate anything 4.5 kilometers beneath the surface of the ocean about a thousand kilometers from land is a massive, massive task, and it is likely to continue for a long time to come." The U.S. Navy commander leading the American effort to find Malaysia Airlines Flight 370 said he's "optimistic" about how the search is proceeding, CNN reports. "We are detecting very continuous pings coming through in a manner consistent with exactly what you'd expect from a black box," Cmdr. William Marks told CNN's Erin Burnett on Friday. "We've ruled out that it was anything natural, or anything from commercial shipping, or anything like that." Australian Prime Minister Tony Abbott said earlier Friday that search efforts are heading in the right direction. Marks said, "I agree with the prime minister. We're optimistic." Up to nine military aircraft, one civil aircraft and 14 ships will assist in Saturday's search for the airliner, Australia's Joint Agency Coordination Centre said in a press release. The center of the 41,393-square-kilometer (16,000 square-mile) search area lies about 2,331 kilometers (1,448 miles) northwest of Perth. During a visit to China, Abbott said, "We have very much narrowed down the search area, and we are very confident that the signals that we are detecting are from the black box." Abbott was referring to the plane's flight data recorder and the cockpit voice recorder. Locator beacons attached to them are designed to emit high-pitched signals, or pings. Over the past week, four such pings have been detected by a ping locator towed by the Australian vessel Ocean Shield. Full story