KUALA LUMPUR, March 21 (Reuters) - If two blurred objects photographed from space are confirmed as debris from Flight MH370, scientists will still face a daunting task to find and recover the sensitive recorders containing clues to the Malaysian jet's disappearance. 
 
 With so little known about why the Beijing-bound Malaysia Airlines flight changed course and disappeared after leaving Kuala Lumpur on March 8, finding the 'black boxes' is seen as the only real hope of understanding what happened to the plane and the 239 people on board. 
 
 Australian Prime Minister Tony Abbott on Thursday said objects possibly belonging to the plane had been discovered in the Indian Ocean. The area is around 2,500 km (1,500 miles) southwest of Perth, above a volcanic ridge in waters estimated to be 2,500 to 4,000 metres (8,200 to 13,120 feet) deep. 
 
 It roughly corresponds to the far end of a southern track the aircraft could have taken after investigators suspect it was deliberately diverted. 
 
 "It can be incredibly rough and difficult. It can be very windy with strong currents, though it can equally be calm," said David Gallo, director of special projects at the Woods Hole Oceanographic Institution (WHOI) in Falmouth, Massachusetts, referring to the general area where the objects were seen. 
 
 Flight MH370's disappearance has been compared to the 2009 Air France jet disaster, which puzzled investigators until a mission led by WHOI found the black boxes in 3,900 metres (12,800 feet) of water. 
 
 But whereas investigators knew roughly where Flight AF447 had hit the Atlantic Ocean on a stormy night in June 2009, search crews know much less about where the Malaysian jet ended up, including whether or where it ran out of fuel. 
 
 "If it is confirmed as debris, then the first priority is to recover and record each piece and see how high or low it is sitting in the water. This may help indicate how it has been moved by currents and winds," said Gallo, who took part in the Air France search. 
 
 DEBRIS COULD HAVE MOVED 
 
 The immediate problem will be to find the debris, which may have moved since the satellite images were taken on March 16. 
 
 It could take several days to verify the satellite lead, a source close to the investigation said. Military aircraft from Australia, the United States and New Zealand have so far found nothing during a search hampered by strong winds and rain. Neither has a merchant ship in the area. 
 
 If the objects - the biggest measures up to 24 metres (79 feet) - are from the Boeing 777, recovery teams will work as quickly as possible to locate the rest of the wreckage in the hope it leads them to the data and cockpit voice recorders. 
 
 To do this, scientists have developed computer models to effectively play waves and winds backwards, allowing rescue workers to retrace the movements of debris to the site of a crash. 
 
 "There are sophisticated models that allow you to work backwards from the current position of each piece of debris, after considering the currents and the winds and so on," said Gallo. 
 
 "That enables you to say X marks the spot on the surface." 
 
 Investigators hope such recent developments in oceanography will help shed light on the baffling disappearance of Flight MH370. 
 
 But not all experts agree computer simulations will easily replace the gruelling routine of searching from the air and the sea. 
 
 Although research has continued since the Air France jet ploughed into the Atlantic, a detailed annex to the report on that disaster, which was blamed mainly on pilot error, raised questions in 2012 over the consistency of such "retro-drift" calculations. 
 
 For example, when the French Navy dropped special buoys at the same spot a year after the crash they scattered hundreds of miles apart, highlighting the turbulence of ocean currents. 
 
 RACE AGAINST TIME 
 
 If the report of suspected debris is confirmed, naval vessels will also drag a sonar through the water to seek the black boxes through radio beacons, but time for this is running out. 
 
 The black boxes are designed to have a battery life of at least 30 days, leaving possibly only 17 days to locate them before the signals die. 
 
 But for every knot, or nautical mile per hour, of current in the rough waters of the southern Indian Ocean, an object could theoretically float for 312 miles (500 km) in 13 days, the time the Malaysian plane has been missing. 
 
 That could present investigators with a much larger potential search area than the 40-mile radius for AF447. 
 
 In 2012, France's BEA air crash investigation agency recommended in its report on the Air France disaster that the battery life on locator beacons be increased to 90 days. 
 
 Although this has been backed by global regulators, it will not become mandatory until towards the end of the decade. 
 
 Other proposals that could potentially make it easier to find MH370 remain bogged down in talks between regulators and the aviation industry, with no timetable for putting them into effect, Reuters reported last week. 
 
 These include adding a new frequency for the beacons so that their signals travel further and can more easily be heard by military ships lacking specialist air crash recovery equipment. 
 
 Existing signals travel about 2,000 to 3,000 metres (6,560 to 9,840 feet) under water, according to the French sea search annex, whereas the area now being combed for debris is up to 4,000 metres deep. 
 
 To close this gap, search teams would bring in boats capable of carrying several miles of cables to drag sonars at lower depths, but experts note moving them into place can take time. 
 
 If by the end of 30 days nothing is found, the search could rely on remote underwater vehicles to scour the seabed. 
 
 To find the Air France wreckage, WHOI used remote-operated REMUS underwater vehicles developed by the U.S. Navy. 
 
 "It was the biggest use of deep-ocean firepower in one spot," Gallo said. (Editing by Dean Yates) ||||| 1 of 7. A fast response craft from Australian Defence Vessel Ocean Shield tows Able Seaman Clearance Diver Michael Arnold as he searches the ocean for debris in the search zone in the southern Indian Ocean for the missing Malaysian Airlines flight MH370 in this picture released by the Australian Defence Force April 8, 2014. 
 
 SYDNEY/PERTH, Australia (Reuters) - An Australian ship which picked up possible "pings" from the black box recorders of a missing Malaysia Airlines jetliner has been unable to detect any further signals and time is running out to narrow the massive search, officials said on Tuesday. 
 
 Angus Houston, head of the Australian agency coordinating the search for Malaysia Airlines Flight MH370, said the month-long hunt in the Indian Ocean was at a critical stage given the batteries in the black box beacons had already reached the end of their 30-day expected life. 
 
 A U.S. Navy "towed pinger locator" onboard Australia's Ocean Shield picked up two signals consistent with black box locator beacons over the weekend - the first for more than two hours and the second for about 13 minutes. 
 
 Houston said the signals represented the best lead in the search yet, but efforts to pick up the pings again had so far been unsuccessful. 
 
 "If we don't get any further transmissions, we have a reasonably large search area of the bottom of the ocean to prosecute and that will take a long, long time. It's very slow, painstaking work," said Houston. 
 
 The black boxes record cockpit data and may provide answers about what happened to the plane, which was carrying 227 passengers and 12 crew when it vanished on March 8 and flew thousands of kilometers off its Kuala Lumpur-to-Beijing route. 
 
 Authorities say evidence, including the loss of communications, suggests the plane was deliberately diverted by someone familiar with the aircraft, but have not ruled out mechanical problems. 
 
 Analysis of satellite data led investigators to conclude the Boeing 777 came down in an area some 1,680 km (1,040 miles) northwest of Perth, near where possible pings were picked up and the search is now focused. 
 
 BLUEFIN ON HOLD 
 
 An autonomous underwater vehicle (AUV) named Bluefin-21 is onboard the Ocean Shield and could be sent to look for wreckage on the sea floor, but narrowing the search zone first was critical, Houston said. 
 
 "It is a large area for a small submersible that has a very narrow field of search, and of course, it is literally crawling along the bottom of the ocean," he said. 
 
 "That's why it's so important to get another transmission and we need to continue until there's absolutely no chance the (black box) device is still transmitting." 
 
 The Bluefin will scour the ocean floor in 20-hour missions using sonar in an attempt to find the aircraft, before its findings are downloaded and analyzed on board the Ocean Shield. 
 
 If anything unusual is spotted, the sonar on board the robotic vehicle will be replaced with a camera to take a closer look. The potential search area is about 4.5 km (2.8 miles) deep, the outer reach of the Bluefin's range. 
 
 Some 133 missions have been completed so far in the multinational aerial hunt for debris in the southern Indian Ocean and would continue, officials said. 
 
 Up to 11 military planes, three civilian planes and 14 ships planned to take part in the search on Tuesday, with good weather in the search area. But so far, searchers have only turned up fishing gear and other detritus. 
 
 "Even after the black box is found, the surface search will continue because they're looking for evidence to investigate why the aircraft went down," Lieutenant Commander Adam Schantz, the officer in charge of U.S. Navy P-8 Poseidon search unit, told Reuters. 
 
 "So, we'll continue for a while trying to find anything on the surface that might give a reasoning behind the accident." 
 
 (Additional reporting by Jane Wardell in Sydney and Anuradha Raghu in Kuala Lumpur; Editing by Dean Yates and Michael Perry) ||||| An Australian plane has spotted an "orange rectangular object" and a "gray or green circular object" while searching for missing Flight 370 in the southern Indian Ocean, officials said. 
 
 Hishamuddin Hussein, Malaysia's acting transport minister, said that Australian Prime Minister Tony Abbott had told his counterpart in Kuala Lumpur that the objects could be retrieved as soon as later Monday by a ship hunting the Boeing 777. 
 
 “A few minutes ago, the prime minister received a call from the prime minister of Australia who informed him that the Australian search aircraft had located two objects in the Australian search area, one circular and one rectangular," Hishamuddin told a media briefing. "HMAS Success is in the vicinity and it is possible that the objects could be received within the next few hours or possibly by tomorrow morning.” 
 
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 The Australian Maritime Safety Authority confirmed that the crew on board a P-3 Orion aircraft "reported seeing two objects – the first a gray or green circular object and the second an orange rectangular object." 
 
 They were spotted around 1,550 miles southwest of Perth, Australia. 
 
 Speaking to Australia's Parliament, Abbott said: "We don’t know whether any of these objects are from MH370. They could be flotsam. Nevertheless we are hopeful that we can recover these objects soon and that they will take us a step closer to resolving this tragic mystery." 
 
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 Oceanographers have been quick to point out that oceans are full of debris so sightings of floating objects may well not be linked to the missing jet. 
 
 David Gallo, an expert based at the Woods Hole Oceanographic Institution, highlighted on Monday that dozens of cargo vessels sink each year -- sending thousands of cargo containers overboard. 
 
 Earlier, authorities said that a U.S. Navy P-8 Poseidon searching for the Malaysia Airlines jet could find no trace of the "suspicious objects" in the southern Indian Ocean that a Chinese aircraft reportedly spotted. 
 
 AMSA said the objects spotted by the Australian searchers were "separate" to the Chinese sighting. 
 
 "We are still racing against time," Chinese Foreign Ministry spokesman Hong Lei told a briefing Monday. "As long as there is a glimmer of hope, our search efforts will carry on." 
 
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 Satellite images and data released by Australia, China and France in recent days have identified possible debris in the area that may be linked to the disappearance of Malaysia Airlines Flight 370 on March 8 with 239 people on board. 
 
 The ocean depth in the search area ranges between 3,770 feet and 23,000 feet, and the U.S. Navy said it was sending a black box locator in case a debris field is located. 
 
 Tom Costello and Emma Ong of NBC News and The Associated Press contributed to this report.
– The search for Flight 370 in its new search zone continues to produce tantalizing sightings, but no links to the plane so far. The latest comes from a Chinese military plane that spotted three suspicious objects today with colors that were at least a rough match for those of the Malaysian jet, reports AP. Australian and Chinese ships were retrieving those and other pieces of debris as quickly as possible for analysis, but it's no easy feat. "It’s an inaccessible place," Australian Prime Minister Tony Abbott told the media, reports the New York Times. "We are trying to find small bits of wreckage in a vast ocean, and while we are throwing everything we have at it, the task goes on.” NBC News, meanwhile, offers a glimmer of hope in regard to figuring out what happened: The plane's black boxes should be able to survive about two years even if submerged in salt water 20,000 feet deep, it says. The deepest part of the new search area is about 13,000 feet.